Mopar1973Man

Here are the fuel pressure requirements for a 1st Generation Dodge Cummins with a Bosch VE injection pump. Maximum Inlet restriction ............................... 4 In Hg Maximum Return line Restriction ................ 20.4 In Hg Maximum pressure drop across fuel filter ............ 5 PSI Maximum pressure at the injection pump .......... 10 PSI Minimum pressure at the injection pump ............. 3 PSI Volume of fuel pumped in 30 seconds ........ 0.79 Quarts The maximum inlet and return line restriction is measured using a vacuum pump against the lines looking for flow restrictions. Minimum and maximum fuel pressure are measured between both idle and WOT operation looking for the performance of the fuel pump are with the specification. The measured fuel pressure should be measured near the injection pump. The volume of fuel is measured by disconnection the fuel line and disconnecting the fuel shutoff solenoid and cranking the engine for 30 seconds. WARNING! Don't crank the engine for more than 30 seconds or starter damage could occur. If you need to repeat the test allow the starter to cool for at least 2-3 minutes before testing again.

Error Codes (Flash Codes) Reading Diagnostic Trouble Codes When the check engine light comes on and stays on (after start-up), this indicates that a code (or codes) has been stored in memory. To retrieve this information for purpose of troubleshooting, cycle the ignition switch ON-OFF-ON-OFF-ON within five seconds. The check engine lamp will then flash the DTC(s). Each code, if there is more than one, will be preceded by a 4 second pause, to distinguish it from the previous code. An example of a DTC would be as follows: * Lamp on for 2 seconds, then turns off. * Lamp flashes 4 times, then pauses, then flashes 1 more time. * Lamp pauses 4 seconds, then flashes 4 times. * Lamp flashes 7 times. The two DTC's displayed, following the two second pause, were 41 and 47. Whenever the malfunction indicator is operated, as many DTC's as are in memory will be displayed. At the end of the sequence, it will flash 55, which indicates it is the end of the stored codes. Mopar1973Man Note: Its still suggested to used a code reader. These errors are very general in description. A normal code reader will show more information. Like error code 43 Ignition coil circuit could be a misfire code (P0300 to P0310) when a error code reader is used you can see the cylinder number. Clearing Diagnostic Trouble Codes When the problem has been sorted out and repaired, you will have to erase the DTC(s) from memory to shut off the CHECK ENGINE light. The proper way to erase is with the DRBII scan tool, or equivalent. If you do not have access to this tool you will have to take the vehicle to a shop that does. If the cause for the blown trouble code is indeed repaired, the memory will automatically be cleared by the engine controller after 50 start-ups. Mopar1973Man Note: Better explanation at this link. Diagnostic Trouble Code Check Engine Light DRB Scan Tool Display Description of DTC 11 No No crank reference signal at PCM No crank reference signal detected during engine cranking. 12 No None Direct battery input to PCM was disconnected with the last 50 key on cycles. 13 Yes No change in MAP from start to run No difference recognized between the engine MAP reading and the atmospheric pressure reading at start up. 14 Yes MAP sensor voltage too high or too low. MAP sensor voltage above or below acceptable voltage. 15 Yes No vehicle speed sensor signal No vehicle distance (speed) sensor detected during road load conditions. 17 No Engine is cold to long Engine coolant temperature remains below normal operating temperatures during vehicle travel. (Faulty thermostat) 21 Yes O² sensor at center Neither rich or lean condition detected from the oxygen sensor input. 22 Yes ECT sensor voltage to high or too low. .Engine Coolant Temperature sensor voltage above or below acceptable voltage. 23 Yes IAT sensor voltage to high or too low Intake Air Temperature sensor voltage above or below acceptable voltage. 24 Yes TPS sensor voltage to high or too low Throttle Position Sensor voltage above or below acceptable voltage. 25 Yes Idle Air Control motor circuits A shorted condition detected in one or more of the idle air control motor circuits. 27 No Injector control circuits (1-8) Injector (1-8) output driver does not respond properly to the control signal. 31 Yes EVAP solenoid circuit An open or shorted condition detected in the EVAP solenoid circuit. 32 Yes EGR solenoid circuit EGR failure An open or shorted condition detected in the Exhaust Gas Recirculation solenoid circuit. A mechanical problem found in the EGR system. (Vacuum leak, defective EGR valve, plugged EGP tube, etc.) 33 No A/C clutch relay circuit An open or shorted condition detected in the Air Conditioning clutch circuit. 34 No Speed control circuits Speed control switch always high or low An open or shorted condition detected in the speed control vacuum and vent solenoid circuits. Speed control switch input above or below acceptable voltage. 37 Yes Torque converter clutch solenoid circuit Trans temp to high or too low An open or shorted condition detected in the CKT solenoid circuit. Voltage to high or too low at the trans temp sensor. 41 Yes Generator field not switch properly An open or shorted condition detected in the generator field control circuit. 42 No Auto Shutdown Relay control circuit An open or shorted condition detected in the ASD relay circuit. 43 Yes Ignition coil circuit An open or shorted condition detected in the EVAP solenoid circuit. (Mis-fire code) 44 No Battery temp sensor volt out of limits An open or shorted condition detected in the engine coolant sensor circuit or a problem exist in the PCM's battery temp voltage circuit. 45 No Trans overdrive solenoid circuit An open or shorted condition detected in the trans overdrive solenoid circuit. 46 Yes Charging system voltage too high Battery voltage sense input above target charging voltage during engine operation. 47 Yes Charging system voltage too low Battery voltage sense input below target charging voltage during engine operation. 51 Yes System lean adap at rich limit Oxygen sensor signal input indicates lean air/fuel ratio condition. 52 Yes System rich adap at lean limit Oxygen sensor signal input indicates rich air/fuel ratio condition. 53 No Internal PCM failure PCM failure SPI (Serial Peripheral Interface) PCM internal fault detected. PCM internal fault detected. 54 No No cam sync signal at PCM No fuel sync (camshaft signal) detected during engine cranking. 55 No Not display on DRB scan tool A DTC #55 is used to end all DTC messages. This code indicates a completion of all DTC's displayed on the Check Engine Light. 62 No PCM Failure SRI miles not stored Unsuccessful attempt to update SRI (service reminder indicator) miles in the EEPROM. 63 No PCM Failure EEPROM write denial Unsuccessful attempt to write to an EEPROM location by the PCM.

P2609 NO VOLTAGE DROP SEEN FROM INTAKE AIR HEATERS When Monitored and Set Condition: When Monitored: First 15 seconds of engine operation. Set Condition: The ECM does not detect a voltage drop on the intake air heater circuit. POSSIBLE CAUSES INTAKE AIR HEATER OPEN INTAKE AIR HEATER GROUND OPEN OPEN BATTERY CABLE FROM INTAKE AIR HEATER RELAY BATTERY CABLE OPEN #1 INTAKE AIR HEATER RELAY #2 INTAKE AIR HEATER RELAY INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. Measure the resistance between the intake air heater supply and ground terminal on each intake air heater. Is the resistance less than 10 Ohms? Yes --> Go To 2 No --> Replace the open Intake Air Heater. Measure the resistance of the intake air heater ground circuit between the intake air heater terminal and the intake manifold cover ground connection. Is the resistance less than 10 Ohms? Yes --> Go To 3 No --> Repair the open Intake Air heater ground. Measure the resistance of the battery cable between the intake air heater and the intake air heater relay for both intake air heaters. Is the resistance less than 10 Ohms? Yes --> Go To 4 No --> Repair The open or high resistance battery cable from the intake heater relay to heater. Measure the resistance of the battery cable between the battery and the intake air heater relay for both relays. Is the resistance less than 10 Ohms? Yes --> Go To 5 No --> Replace the battery cable from the battery to the Intake Air Heater Relay. Disconnect the #1 intake air heater relay signal wire. Connect a jumper wire from the signal terminal of the #1 intake air heater relay to battery positive. Did the relay click when 12 volts was applied? Yes --> Go To 6 No --> Replace #1 Intake Air Heater Relay. Disconnect the #2 intake air heater relay signal wire. Connect a jumper wire from the signal terminal of the #2 intake air heater relay to battery positive. Did the relay click when 12 volts was applied? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). No --> Replace #2 Intake Air Heater Relay.

P2608 HIGH VOLTAGE AT THE #2 INTAKE AIR HEATER RELAY When Monitored: When the ignition is on. Set Condition: When the signal from the #2 Intake Air Heater output does not match the signal from the #2 Intake Air Heater feedback. POSSIBLE CAUSES LOOSE CONNECTION INTAKE AIR HEATER RELAY SIGNAL CIRCUIT SHORTED TO BATTERY NEGATIVE ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE Ignition on, engine not running. With the DRBIII®, actuate the Intake Air Heater relay. Can you hear the Relay clicking? Yes --> Go To 2 No --> Go To 3 2. While the relay is clicking, wiggle the wiring harness and connectors. Does this interrupt the clicking? Yes --> Repair the poor connection. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 3 3. Turn the ignition off. Remove the Intake Air Heater Relay. Check connectors - Clean/repair as necessary. Measure the resistance between the signal and return posts of the intake air heater relay. Is the resistance between 15 and 25 Ohms? Yes --> Go To 4 No --> Replace the Intake Air Heater relay. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). 4. Disconnect the ECM harness connector(s). Check connectors - Clean/repair as necessary. Measure the resistance between the signal circuit of the intake air heater relay and battery negative. Is the resistance greater than 100 K ohms? Yes --> Go To 5 No --> Repair signal circuit shorted to battery negative. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). 5. Reconnect the ECM harness connectors. Turn the ignition on. Disconnect the intake air heater relay signal wire. Did DTC P0542 or 2608 set? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace the ECM. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2607 LOW VOLTAGE AT THE #2 INTAKE AIR HEATER RELAY When Monitored: When the ignition is on. Set Condition: When the signal from the #1 intake air heater output does not match the signal from the #1 intake air heater feedback. POSSIBLE CAUSES LOOSE CONNECTION INTAKE AIR HEATER RELAY SIGNAL CIRCUIT OPEN FROM RELAY TO ECM SIGNAL CIRCUIT SHORTED TO BATTERY NEGATIVE ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE Ignition on, engine not running. With the DRBIII®, actuate the #1 Intake Air Heater. Can you hear the Relay clicking? Yes --> Go To 2 No --> Go To 3 While the relay is clicking, wiggle the wiring harness and connectors. Does this interrupt the clicking? Yes --> Repair the poor connection. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 3 Turn the ignition off. Remove the Intake Air Heater #1 Relay. Check connectors - Clean/repair as necessary. Measure the resistance between the signal and return posts of the intake air heater relay. Is the resistance between 15 and 25 Ohms? Yes --> Go To 4 No --> Replace the Intake Air Heater #1 relay. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Disconnect the ECM harness connectors. Check connectors - Clean/repair as necessary. Measure the resistance of the intake air heater relay signal circuit between the ECM connector and the intake air heater relay connector. Is the resistance less than 10 Ohms? Yes --> Go To 5 No --> Repair the open signal circuit from PDC to ECM harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the signal circuit of the intake air heater relay and battery negative. Is the voltage greater than 1 volts? Yes --> Repair the signal circuit shorted to Battery negative. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 6 Reconnect the ECM harness connectors. Disconnect the intake air heater relay signal wire and use a jumper to connect it to battery negative. Turn the ignition on. With the DRBIII®, read DTCs. Did DTC P0542 set or P2608? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace the ECM. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2509 POWERDOWN DATA LOST ERROR When Monitored and Set Condition: When Monitored: Continuous - key on or key off. Set Condition: Loss of voltage detected at the ECM for a calibrated amount of time. POSSIBLE CAUSES POOR CONNECTIONS AT THE BATTERIES LOW BATTERY VOLTAGE OPEN FUSED B+ TO ECM OPEN GROUND CIRCUIT BATTERY + SHORTED TO OTHER CIRCUITS RETURN CIRCUIT SHORTED BATTERY + SHORTED TO GROUND INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. Visually inspect the wiring at the battery for damaged wires, or corrosion. Are the connections tight and free of corrosion? Yes --> Go To 2 No --> Repair the poor connections at the batteries. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the positive and negative posts of the batteries. Is the battery voltages both above 12 volts? Yes --> Go To 3 No --> Recharge or replace the battery (s). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Disconnect the ECM harness connectors. Turn the ignition on. Measure the resistance between the positive battery post and the ECM supply circuits. Is the resistance less than 10 Ohms? Yes --> Go To 4 No --> Repair the open fused B+ circuit to ECM. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the negative battery post and the ECM ground wire. Is the resistance less than 10 Ohms? Yes --> Go To 5 No --> Repair the open ground circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the ECM supply circuits and all other circuits in the ECM harness connector, except other supply circuits. Is the resistance greater than 100k Ohms? Yes --> Go To 6 No --> Repair the battery circuit short to other circuits in engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the ECM return circuits and all other circuits in the ECM harness connector, except other return circuits. Is the resistance greater than 100k Ohms? Yes --> Go To 7 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the ECM B+ supply circuit and ground. Is the resistance greater than 100k Ohms? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Repair Battery + shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2504 CHARGING SYSTEM OUTPUT HIGH When Monitored and Set Condition: When Monitored: While the engine is running. Set Condition: Battery voltage is less than 11.5 volts for more than 8 seconds. Battery voltage must exceed 12 volts for more than 5 seconds for fault to become inactive. POSSIBLE CAUSES OTHER DTC'S PRESENT DIRTY OR LOOSE CONNECTIONS ADD-ON OR ACCESSORY WIRES AT BATTERY TERMINAL HIGH RESISTANCE IN THE B+ CIRCUIT HIGH RESISTANCE IN THE B+ CROSS OVER CABLE HIGH RESISTANCE IN THE GROUND CIRCUIT GENERATOR ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. With the DRBIII®, read DTCs. Is DTC P2502 set? Yes --> Repair other DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 2 Visually inspect the positive and negative connections at the battery. Visually inspect the battery negative connections at the engine block. Are the connections free of corrosion and are they tight? Yes --> Go To 3 No --> Clean and/or tighten the connections. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Check for add-on or accessory wiring at positive (+) terminal of the battery. Are there any damaged wires at the battery? Yes --> Remove defective or miss wired add-on or accessory wiring from battery. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 4 Measure the voltage between the B+ post of the generator and the B+ post of the battery while the engine is running. Is the voltage above .4 volts? Yes --> Repair the high resistance in the B+ circuit from battery to the generator. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 5 Measure the voltage between the B+ post of the generator and the B+ post of the right side battery to the left side battery while the engine is running. Is the voltage above .4 volts? Yes --> Repair the high resistance in the B+ cross over cable from right side battery to left side battery. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 6 Measure the voltage between the generator case and the B- post of the battery. Is the voltage above .1 volts? Yes --> Repair the high resistance in the ground circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 7 Disconnect the Generator field harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the generator field terminals at the generator. Is the resistance between .5 and 15 Ohms? Yes --> Go To 8 No --> Replace the generator. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure and record the voltage between battery positive circuit of the ECM harness connector and the battery negative circuits of the ECM harness connector. Reconnect the ECM connectors. Use the DRBIII® to measure and record battery voltage. Compare the voltage reading from the voltmeter with that of the DRBIII®. Are the readings within 3 volts of each other? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2503 CHARGING SYSTEM OUTPUT LOW When Monitored and Set Condition: When Monitored: While the engine is running. Set Condition: The battery voltage exceeds target voltage by more than a calibrated value. POSSIBLE CAUSES OTHER DTC'S PRESENT GENERATOR FIELD DRIVER CIRCUIT SHORTED TO GROUND ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. With the DRBIII®, read DTCs. Is DTC P2502 set? Yes --> Repair other DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 2 Disconnect the Generator field harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the generator field terminals at the generator. Is the resistance between .5 and 15 Ohms? Yes --> Go To 3 No --> Replace the generator. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Disconnect the ECM harness connectors. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the generator field driver circuit between the generator and battery negative. Is the resistance greater than 100 ohms? Yes --> Go To 4 No --> Repair the generator field driver circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure and record the voltage between battery positive circuit of the ECM harness connector and the battery negative circuits of the ECM harness connector. Reconnect the ECM connectors. Use the DRBIII® to measure and record battery voltage. Compare the voltage reading from the voltmeter with that of the DRBIII®. Are the readings within 3 volts of each other? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2502 CHARGING SYSTEM ERROR When Monitored and Set Condition: When Monitored: While the engine is running. Set Condition: The ECM cycles the voltage regulator in the generator while monitoring for a change in output voltage. If the voltage does not drop when the regulator is off, the fault is set. POSSIBLE CAUSES DIRTY OR LOOSE CONNECTIONS HIGH RESISTANCE IN THE B+ CIRCUIT HIGH RESISTANCE IN THE B+ CROSS OVER CABLE HIGH RESISTANCE IN THE GROUND CIRCUIT GENERATOR ECM INTERMITTENT CONDITION DIAGNOIST PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. Visually inspect the positive and negative connections at the battery. Visually inspect the battery negative connections at the engine block. Are the connections free of corrosion and are they tight? Yes --> Go To 2 No --> Clean and/or tighten the connections. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL). Measure the voltage between the B+ post of the generator and the B+ post of the battery while the engine is running. Is the voltage above .4 volts? Yes --> Repair the high resistance in the B+ circuit from battery to the generator. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL). No --> Go To 3 Measure the voltage between the B+ post of the generator and the B+ post of the right side battery to the left side battery while the engine is running. Is the voltage above .4 volts? Yes --> Repair the high resistance in the B+ cross over cable from right side battery to left side battery. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL). No --> Go To 4 Measure the voltage between the generator case and the B- post of the battery. Is the voltage above .1 volts? Yes --> Repair the high resistance in the ground circuit. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL). No --> Go To 5 Disconnect the Generator field harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the generator field terminals. Is the resistance between .5 and 15 Ohms? Yes --> Go To 6 No --> Replace the generator. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL). Turn the ignition off. Reconnect the Generator field harness connector. Disconnect the ECM harness connectors. NOTE: Check connectors - Clean/repair as necessary. Ignition on, engine not running. Measure and record the voltage between battery positive circuits of the ECM harness connector and the battery negative circuits of the ECM harness connector. Turn the ignition off. Reconnect the ECM harness connectors. Start the engine. Use the DRBIII® to measure and record battery voltage. Compare the voltage reading from the voltmeter with that of the DRBIII®. Are the readings within 3 volts of each other? Yes --> Test Complete. No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL).

P2266 WATER IN FUEL (WIF) SENSOR VOLTAGE TOO LOW When Monitored and Set Condition: When Monitored: Ignition on. Set Condition: Low voltage detected at the WIF signal circuit at the ECM. POSSIBLE CAUSES OTHER DTC'S PRESENT WATER IN FUEL ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. With the DRBIII®, read DTCs. Do you have any additional water in fuel DTCs? Yes --> Repair other Water in fuel sensor DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 2 Using the service publications as a guide, drain the water in fuel separator. Did the DTC become inactive after draining the water in fuel separator? Yes --> Clear DTC, repair complete. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 3 Disconnect the WIF sensor harness connector. NOTE: Check connectors - Clean/repair as necessary. Using the DRBIII®, monitor for DTCs while connecting a jumper wire between the (G123) signal circuit of the water in fuel sensor and battery voltage. Did the water in fuel light go out? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2149 BANK 2 (CYLINDERS 4-6) SHORTED HIGH OR LOW When Monitored and Set Condition: When Monitored: While the engine is running. Set Condition: A misfire detected at cylinders 4,5, or 6 or any combination of cylinders 4,5, or 6. POSSIBLE CAUSES OTHER DTC'S HIGH SIDE DRIVER CIRCUIT OPEN LOW SIDE DRIVER CIRCUIT OPEN HIGH SIDE DRIVER SHORTED TO LOW SIDE DRIVER HIGH SIDE DRIVERS SHORTED LOW LOW SIDE DRIVER CIRCUIT SHORTED OTHER LOW SIDE DRIVER CIRCUIT LOW SIDE DRIVERS SHORTED LOW HIGH SIDE DRIVER SHORTED TO VOLTAGE LOW SIDE DRIVER SHORTED TO VOLTAGE LOW SIDE DRIVER CIRCUIT SHORTED IN INJECTOR HARNESS INJECTOR INJECTOR HARNESS INTERMITTENT CONDITION ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. With the DRBIII®, read DTCs. Do you have any combination of DTCs P0201, P0202, or P0203? Yes --> Repair other DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 2 Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the Injector 4-6 harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the injector high side driver circuit between the Bank 2 high side driver circuit in the ECM harness connector and the high side driver circuit in the injector harness connectors for cylinders 4-6. Is the resistance less than 10 Ohms? Yes --> Go To 3 No --> Repair the open high side driver circuit from ECM harness connector to the Injector harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the #4,#5, and #6 injector low side driver circuits between the ECM harness connector and the injector harness connectors. Is the resistance less than 10 Ohms? Yes --> Go To 4 No --> Repair the open low side driver circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the Bank 2 high side driver circuit at the ECM harness connector and the low side driver circuit for injectors 4-6 at the ECM harness connector. Is the resistance more than 100k Ohms? Yes --> Go To 5 No --> Repair the High side circuit shorted to the low side circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the injector harness connector high side driver circuits to battery negative for injectors 4-6. Is the resistance more than 100k Ohms? Yes --> Go To 6 No --> Repair the High side driver shorted low in the harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the injector harness connector Low side driver circuits to battery negative for injectors 4-6. Is the resistance more than 100k Ohms? Yes --> Go To 7 No --> Repair the Low side driver shorted low in the harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the high side driver circuit in the engine harness and battery negative. Is the voltage less than 1 volt? Yes --> Go To 8 No --> Repair the high side driver shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the low side driver circuit in the engine harness and battery negative for cylinders 4-6. Is the voltage less than 1 volt? Yes --> Go To 9 No --> Repair the low side driver shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of each of the Bank 2 low side driver circuit to all other Bank 1 low side driver circuits at the ECM harness connector. Is the resistance greater than 100k ohms? Yes --> Go To 10 No --> Repair Low side driver circuit shorted to other Low side driver circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the disconnected injector harness connector. Measure the resistance of each of the Bank 2 low side driver circuit to all other Bank 2 low side driver circuit at the ECM harness connector. Is the resistance greater than 100k ohms? Yes --> Go To 11 No --> Replace the injector harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of each injector from the through head connector. NOTE: Be sure to zero the ohm meter prior to checking the injector circuit. Is the resistance greater than .8 ohm? Yes --> Go To 12 No --> Go To 14 Disconnect the pigtail nuts from injectors 4-6. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the solenoid posts of each injector. NOTE: Be sure to zero the ohm meter prior to checking the injector circuit. Is the resistance less than 1 ohm and greater than 0 ohms? Yes --> Go To 13 No --> Replace the fuel injector or injectors. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure resistance of each circuit in the injector harness from pigtail side to injector harness connector. Is resistance above 1 ohm? Yes --> Replace the injector harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the all injector pig tails harness connector. Reconnect the ECM harness connector. Reconnect the Injector harness connector. Start the engine. With the DRBIII®, read DTCs. Did the DTC return? Yes --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Test Complete.

P2146 BANK 1 (CYLINDERS 1-3) SHORTED HIGH OR LOW When Monitored and Set Condition: When Monitored: While the engine is running. Set Condition: A circuit failure detected at cylinders 1,2, or 3 or any combination of cylinders 1,2, or 3. POSSIBLE CAUSES OTHER DTC'S HIGH SIDE DRIVER CIRCUIT OPEN LOW SIDE DRIVER CIRCUIT OPEN HIGH SIDE DRIVER SHORTED TO LOW SIDE DRIVER HIGH SIDE DRIVERS SHORTED LOW LOW SIDE DRIVER CIRCUIT SHORTED OTHER LOW SIDE DRIVER CIRCUIT LOW SIDE DRIVERS SHORTED LOW HIGH SIDE DRIVER SHORTED TO VOLTAGE LOW SIDE DRIVER SHORTED TO VOLTAGE LOW SIDE DRIVER CIRCUIT SHORTED IN INJECTOR HARNESS INJECTOR INJECTOR HARNESS INTERMITTENT CONDITION ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. With the DRBIII®, read DTCs. Do you have any combination of DTCs P0201, P0202, or P0203? Yes --> Repair other DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 2 Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the Injector 1-3 harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the injector high side driver circuit between the Bank 1 high side driver circuit in the ECM harness connector and the high side driver circuit in the injector harness connectors for cylinders 1-3. Is the resistance less than 10 Ohms? Yes --> Go To 3 No --> Repair the open high side driver circuit from ECM harness connector to the Injector harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the #1,#2, and #3 injector low side driver circuits between the ECM harness connector and the injector harness connectors. Is the resistance less than 10 Ohms? Yes --> Go To 4 No --> Repair the open low side driver circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the Bank 1 high side driver circuit at the ECM harness connector and the low side driver circuit for injectors 1-3 at the ECM harness connector. Is the resistance more than 100k Ohms? Yes --> Go To 5 No --> Repair the High side circuit shorted to the low side circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the injector harness connector high side driver circuits to battery negative for injectors 1-3. Is the resistance more than 100k Ohms? Yes --> Go To 6 No --> Repair the High side driver shorted low in the harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the injector harness connector Low side driver circuits to battery negative for injectors 1-3. Is the resistance more than 100k Ohms? Yes --> Go To 7 No --> Repair the Low side driver shorted low in the harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the high side driver circuit in the engine harness and battery negative. Is the voltage less than 1 volt? Yes --> Go To 8 No --> Repair the high side driver shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the low side driver circuit in the engine harness and battery negative for cylinders 1-3. Is the voltage less than 1 volt? Yes --> Go To 9 No --> Repair the low side driver shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of each of the Bank 1 low side driver circuit to all other Bank 1 low side driver circuits at the ECM harness connector. Is the resistance greater than 100k ohms? Yes --> Go To 10 No --> Repair Low side driver circuit shorted to other Low side driver circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the disconnected injector harness connector. Measure the resistance of each of the Bank 1 low side driver circuit to all other Bank 1 low side driver circuit at the ECM harness connector. Is the resistance greater than 100k ohms? Yes --> Go To 11 No --> Replace the injector harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of each injector from the through head connector. NOTE: Be sure to zero the ohm meter prior to checking the injector circuit. Is the resistance greater than .8 ohm? Yes --> Go To 12 No --> Go To 14 Disconnect the pigtail nuts from injectors 1-3. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the solenoid posts of each injector. NOTE: Be sure to zero the ohm meter prior to checking the injector circuit. Is the resistance less than 1 ohm and greater than 0 ohms? Yes --> Go To 13 No --> Replace the fuel injector or injectors. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure resistance of each circuit in the injector harness from pigtail side to injector harness connector. Is resistance above 1 ohm? Yes --> Replace the injector harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the all injector pig tails harness connector. Reconnect the ECM harness connector. Reconnect the Injector harness connector. Start the engine. With the DRBIII®, read DTCs. Did the DTC return? Yes --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2128 HIGH VOLTAGE AT THE THROTTLE VALIDATION SWITCH When Monitored and Set Condition: When Monitored: Key on. Set Condition: Both Idle and Not Idle switches are in the same state simultaneously for a calibrated amount of time. POSSIBLE CAUSES (K565) IDLE SWITCH CIRCUIT SHORTED TO (K922) RETURN CIRCUIT (K556) NOT IDLE SWITCH CIRCUIT SHORTED TO (K922) RETURN CIRCUIT (K565) IDLE SWITCH CIRCUIT SHORTED TO GROUND (K556) NOT IDLE SWITCH CIRCUIT SHORTED TO GROUND (K565) IDLE SWITCH SHORTED TO (K556) NOT IDLE SWITCH (K565) IDLE SWITCH SHORTED TO (K556) NOT IDLE SWITCH INSIDE ECM ECM INTERMITTENT CONDITION (K29) APPS NO.2 SIGNAL CIRCUIT SHORTED TO (K854) APPS NO.2 5-VOLT SUPPLY CIRCUIT (K29) APPS NO.2 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS IN THE ECM HARNESS ECM APPS INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. The diesel engine uses two types of throttle position sensors, depending on transmission configuration. Is the throttle position sensor is located on the engine? Yes --> Go To 2 No --> Go To 9 Turn the ignition off. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Ignition on, engine not running. Measure the voltage between the (K565) idle switch circuit of the APPS harness connector and (K922) return circuit. Is the voltage between 4.5 and 5.5 volts? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 3 Measure the voltage between the (K556) not idle switch circuit of the APPS harness connector and (K922) return circuit. Is the voltage between 4.5 and 5.5 volts? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 4 Turn the ignition off. Disconnect the ECM harness connectors. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the (K565) idle switch circuit of the APPS harness connector and battery negative. Is the resistance greater than 100 K Ohms? Yes --> Go To 5 No --> Repair the (K565) Idle switch circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K556) not idle switch circuit of the APPS harness connector and battery negative. Is the resistance greater than 100 K Ohms? Yes --> Go To 6 No --> Repair the (K556) not Idle switch circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K65) idle switch circuit of the APPS harness connector and the (K556) not idle switch circuit of the APPS harness connector. Is the resistance less than 10 Ohms? Yes --> Repair the (K565) idle switch circuit shorted to the not (K556) not idle switch circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 7 Reconnect the ECM harness connectors. Measure the resistance between the (K565) idle switch circuit of the APPS harness connector and the (K556) not idle switch circuit of the APPS harness connector. Is the resistance less than 10 Ohms? Yes --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 8 Ignition on, engine not running. Measure the voltage between the (K565) idle switch circuit of the APPS harness connector and battery negative. Is the voltage between 4.5 and 5.5 volts? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the (K29) APPS No. 2 signal circuit in the sensor harness connector and the (K854) APPS No. 2 5-volt supply circuit in the sensor harness connector. Is the resistance greater than 100 K ohms? Yes --> Go To 10 No --> Repair the (K29) APPS No. 2 signal circuit shorted to (K854) APPS No. 2 5-volt supply circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the APPS No. 2 signal circuit at the ECM harness connector and all other circuit in the ECM harness connector. Is the resistance greater than 100 K ohms? Yes --> Go To 11 No --> Repair the (K29) APPS No. 2 Signal circuit shorted to other circuits in the ECM harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the ECM harness connector. Reconnect the APPS harness connector. Ignition on, engine not running. While monitoring the DRBIII®, disconnect the APPS harness connector. Did DTC P2122 and P2127 set? Yes --> Go To 12 No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the APPS harness connector. Monitor the APPS No. 1 and APPS No. 2 voltage with the DRBIII® while depressing the throttle pedal. Is the voltage transition shown on the DRBIII® smooth while depressing the throttle Yes --> Test Complete. No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2127 LOW VOLTAGE AT THE THROTTLE VALIDATION SWITCH When Monitored and Set Condition: When Monitored: Key on. NOTE: This DTC will remain active until the accelerator pedal is cycled. Be sure to cycle the accelerator pedal after completing any repairs to this circuit and prior to checking DTC status with the. DRBIII® Set Condition: Both Idle and Not Idle switches are in the same state simultaneously for a calibrated amount of time. POSSIBLE CAUSES APPS IDLE SWITCH APPS NOT IDLE SWITCH IDLE SWITCH CIRCUIT OPEN NOT IDLE SWITCH CIRCUIT OPEN APPS RETURN CIRCUIT OPEN IDLE SWITCH CIRCUIT SHORTED TO VOLTAGE NOT IDLE SWITCH CIRCUIT SHORTED TO VOLTAGE ECM APPS 2 SIGNAL CIRCUIT OPEN INTERMITTENT CONDITION 5-VOLT SUPPLY CIRCUIT OPEN APPS 2 SIGNAL CIRCUIT SHORTED TO GROUND APPS 2 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND APPS 2 SIGNAL CIRCUIT SHORTED APPS 2 5-VOLT SUPPLY CIRCUIT SHORTED APPS ECM INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. The diesel engine uses two types of throttle position sensors, depending on transmission configuration. Is the throttle position sensor is located on the engine? Yes --> Go To 2 No --> Go To 10 Turn the ignition off. Disconnect the APPS harness connector. Turn the ignition on. NOTE: Check connectors - Clean/repair as necessary. Measure the voltage between the idle switch circuit of the APPS harness connector and sensor #1 return circuit. Is the voltage between 4.5 and 5.5 volts? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 3 Measure the voltage between the not idle switch circuit of the APPS harness connector and sensor #1 return circuit. Is the voltage between 4.5 and 5.5 volts? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 4 Turn the ignition off. Disconnect the ECM harness connector(s). NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the idle switch circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 Ohms? Yes --> Go To 5 No --> Repair the open idle switch circuit from the ECM harness connector to the APPS harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the not idle switch circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 Ohms? Yes --> Go To 6 No --> Repair the open not idle switch circuit from the ECM harness connector to the APPS harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS #1 return circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 Ohms? Yes --> Go To 7 No --> Repair the open APPS return circuit from the ECM harness connector to the APPS harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the idle switch circuit of the APPS connector and battery negative. Is the voltage less than 1 volt? Yes --> Go To 8 No --> Repair the shorted to voltage idle switch circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the voltage between the not idle switch circuit of the APPS connector and battery negative. Is the voltage less than 1 volt? Yes --> Go To 9 No --> Repair the shorted to voltage not idle switch circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the ECM harness connector. Measure the voltage between the idle switch circuit of the APPS connector and APPS return circuit. Is the voltage between 4.5 and 5.5 volts? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the APPS 2 signal circuit between the APPS harness connector and the ECM harness connector Is the resistance less than 10 ohms? Yes --> Go To 11 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS 2 5-volt supply circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 12 No --> Repair the open 5-volt supply circuit or replace the wiring harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS 2 signal circuit between the APPS harness connector and battery negative. Is the resistance less than 100 ohms? Yes --> Go To 13 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS 2 5-volt supply circuit between the APPS harness connector and battery negative. Is the resistance less than 100 ohms? Yes --> Go To 14 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS 2 signal circuit between the APPS harness connector and all other circuits in the ECM harness connector. Is the resistance less than 100 ohms? Yes --> Go To 15 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the APPS 2 5-volt supply circuit between the APPS harness connector and all other circuits in the ECM harness connector. Is the resistance less than 100 ohms? Yes --> Go To 16 No --> Repair or replace the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the ECM harness connectors. Ignition on, engine not running. While monitoring with the DRBIII®, connect a jumper wire between the APPS 2 signal circuit at the sensor harness connector and the APPS 2 5-volt supply circuit at the sensor harness connector. NOTE: With the sensor disconnected it is normal to have a APPS 1 and APPS 2 low voltage DTC set. Did a APPS 2 voltage too high DTC set? Yes --> Go To 17 No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Reconnect the APPS harness connector. Ignition on, engine not running. Monitor the APPS 1 and APPS 2 voltage with the DRBIII® while depressing the throttle pedal. Is the voltage transition shown on the DRBIII® smooth while depressing the throttle Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2123 HIGH VOLTAGE AT THE APP SENSOR When Monitored and Set Condition: When Monitored: While the key is on and during engine operation. Set Condition: The APPS signal circuit voltage at the ECM goes above 4.24 volts for more than 2 seconds. POSSIBLE CAUSES APPS (K922) RETURN CIRCUIT OPEN (K22) SIGNAL CIRCUIT SHORTED TO (K851) 5-VOLT SUPPLY (K22) SIGNAL CIRCUIT SHORTED TO VOLTAGE ECM INTERMITTENT CONDITION (K167) APPS NO. 1 RETURN CIRCUIT OPEN (K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO (K852) APPS NO. 1 5-VOLT SUPPLY (K23) APPS SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures. The diesel engine uses two types of throttle position sensors, depending on transmission configuration. Is the throttle position sensor is located on the engine? Yes --> Go To 2 No --> Go To 9 Turn the ignition off. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the (K22) signal circuit of the sensor to the (K851) 5-volt supply circuit of the sensor. Is the resistance between 1500 - 3000 Ohms with the accelerator pedal released? Yes --> Go To 3 No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K22) signal circuit of the sensor to the (K851) 5-volt supply circuit of the sensor. NOTE: Released resistance must be at least 1000 Ohms greater than depressed resistance. Is the resistance between 200 - 1500 Ohms with the accelerator pedal depressed? Yes --> Go To 4 No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the APPS harness connector. Ignition on, engine not running. Using the DRBIII®, monitor the DTC while disconnecting the APPS harness connector Did P2122 set? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 5 Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the APPS (K922) return circuit between the sensor harness connector and the ECM harness connector. Is the resistance less than 10 Ohms? Yes --> Go To 6 No --> Repair the open (K922) return circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K22) signal circuit in the sensor harness connector and the (K851) 5- volt supply circuit in the sensor harness connector. Is the resistance less than 10 Ohms? Yes --> Repair the (K22) signal circuit shorted to (K851) 5-volt supply circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 7 Measure the voltage between the (K22) signal circuit in the sensor harness connector and battery negative. Is the voltage greater than 1 volt? Yes --> Repair the (K22) signal circuit shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 8 Reconnect the ECM harness connectors. Reconnect the disconnected APPS harness connector. Monitor the DRBIII® while disconnecting the APPS harness connector. Did P2122 set? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Disconnect the APPS harness connector. Disconnect the ECM harness connectors. Measure the resistance on the (K167) APPS No. 1 return circuit between the sensor harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 10 No --> Repair the (K167) APPS No. 1 return circuit open. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K23) APPS No. 1 signal circuit in the sensor harness connector and the (K852) APPS No. 1 5-volt supply circuit in the sensor harness connector. Is the resistance greater than 100 K ohms? Yes --> Go To 11 No --> Repair the (K23) APPS No. 1 signal circuit shorted to the (K852) 5-volt supply circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the APPS No. 1 signal circuit at the ECM harness connector and all other circuits in the ECM harness connector. Is the resistance greater than 100 k ohms? Yes --> Go To 12 No --> Repair the (K23) APPS No. 1 signal circuit shorted to another circuit in the engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the ECM harness connectors. Reconnect the APPS harness connector. While monitoring with the DRBIII®, disconnect the sensor connector. Did a APPS No. 1 and APPS No. 2 voltage too low DTC set? Yes --> Go To 13 No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the APPS harness connector. Monitor the APPS No. 1 and APPS No. 2 voltage with the DRBIII® while depressing the throttle pedal. Is the voltage transition shown on the DRBIII® smooth while depressing the throttle? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P2122 LOW VOLTAGE AT THE APP SENSOR When Monitored and Set Condition: When Monitored: While the key is on and during engine operation. Set Condition: The APPS circuit voltage at the ECM goes below 0.13 volt for more than 2 seconds. POSSIBLE CAUSES APPS (K851) 5-VOLT SUPPLY CIRCUIT OPEN (K22) SIGNAL CIRCUIT OPEN FROM ECM TO APPS (K22) SIGNAL CIRCUIT SHORTED TO (K922) RETURN CIRCUIT (K22) SIGNAL CIRCUIT SHORTED TO GROUND (K22) SIGNAL CIRCUIT SHORTED TO (K914) SENSOR RETURN (K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K922) RETURN CIRCUIT (K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K914) SENSOR RETURN (K851) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND (K22) SIGNAL CIRCUIT SHORTED TO (K565) IDLE CIRCUIT (K22) SIGNAL CIRCUIT SHORTED TO (K556) NOT IDLE CIRCUIT ECM INTERMITTENT CONDITION (K23) APPS NO. 1 SIGNAL CIRCUIT OPEN (K852) APPS NO. 1 5-VOLT SUPPLY OPEN (K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND (K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS (K852) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND (K852) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS INTERMITTENT CONDITION DIAGNOSTIC PROCEDURE The diesel engine uses two types of throttle position sensors, depending on transmission configuration. Is the throttle position sensor is located on the engine? Yes --> Go To 2 No --> Go To 17 Turn the ignition off. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the (K22) signal circuit of the sensor to the (K851) 5-volt supply circuit of the sensor. Is the resistance between 1500 - 3000 Ohms with the accelerator pedal released? Yes --> Go To 3 No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K22) signal circuit of the sensor to the (K851) 5-volt supply circuit of the sensor. NOTE: Released resistance must be at least 1000 Ohms greater than depressed resistance. Is the resistance between 200 - 1500 Ohms with the accelerator pedal depressed? Yes --> Go To 4 No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K851) 5-volt supply circuit of the sensor and the (K922) return circuit of the sensor. Is the resistance between 2000 and 3000 Ohms, depressed as well as released? Yes --> Go To 5 No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Connect a jumper wire between the (K22) signal circuit in the sensor harness connector and the (K851) 5-volt supply circuit in the sensor harness connector. With the DRBIII®, read DTCs. Did P2123 set? Yes --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 6 Disconnect the ECM harness connectors. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the (K851) 5-volt supply circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 7 No --> Repair the open (K851) 5-volt supply circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the (K22) signal circuit between the APPS harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 8 No --> Repair the open (K22) signal circuit from ECM to APPS harness connector. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K22) signal circuit in the sensor harness connector and the (K922) return circuit in the sensor harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K22) signal circuit shorted to the (K922) return circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 9 Measure the resistance between the (K22) signal circuit in the sensor harness connector and battery negative. Is the resistance less than 10 ohms? Yes --> Repair the (K22) signal circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 10 Measure the resistance between the (K22) signal circuit in the sensor harness connector and the (K914) sensor return circuit of the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K22) signal circuit shorted to the (K914) sensor return circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 11 Measure the resistance between the (K851) 5-volt supply circuit in the sensor harness connector and the (K922) return circuit in the sensor harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K851) 5-volt supply circuit shorted to the (K922) return circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 12 Measure the resistance between the (K851) 5-volt supply circuit in the sensor harness connector and battery negative. Is the resistance less than 10 ohms? |Yes --> Repair the (K851) 5-volt supply circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 13 Measure the resistance between the (K851) 5-volt supply circuit in the sensor harness connector and the (K914) sensor return circuit of the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K851) 5-volt supply circuit shorted to the (K914) sensor return circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 14 Measure the resistance between the (K22) signal circuit in the sensor harness connector and the (K565) idle switch circuit in the sensor harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K22) signal circuit shorted to the (K565) idle circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 15 Measure the resistance between the (K22) signal circuit in the sensor harness connector and the (K556) not idle switch circuit in the sensor harness connector. Is the resistance less than 10 ohms? Yes --> Repair the (K22) signal circuit shorted to the (K556) not idle circuit. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Go To 16 Reconnect the ECM harness connectors. Ignition on, engine not running. Connect a jumper wire between the (K22) signal circuit in the sensor harness connector and the (K851) 5-volt supply circuit in the sensor harness connector. Did DTC P2123 set? Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the APPS harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the (K23) APPS No. 1 signal circuit between the APPS sensor harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 18 No --> Repair the (K23) APPS No. 1 signal circuit open. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance of the (K852) APPS No. 1 5-volt supply circuit between the APPS sensor harness connector and the ECM harness connector. Is the resistance less than 10 ohms? Yes --> Go To 19 No --> Repair the (K852) APPS No. 1 5-volt supply open. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K23) APPS No. 1 signal circuit at the sensor harness connector and battery negative. Is the resistance greater than 100 k ohms? Yes --> Go To 20 No --> Repair the (K23) APPS No. 1 signal circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K23) APPS No. 1 signal circuit at the sensor harness connector and all other circuits in the ECM harness connector. Is the resistance greater than 100 k ohms? Yes --> Go To 21 No --> Repair the (K23) APPS No. 1 signal circuit shorted to other circuits. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K852) APPS No. 1 5-volt supply circuit at the sensor harness connector and battery negative. Is the resistance greater than 100 k ohms? Yes --> Go To 22 No --> Repair the (K852) APPS No. 1 5-volt supply circuit shorted to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Measure the resistance between the (K852) APPS No. 1 5-volt supply circuit at the sensor harness connector and all other circuits in the ECM harness connector. Is the resistance greater than 100 k ohms? Yes --> Go To 23 No --> Repair the (K852) APPS No. 1 5-volt supply circuit shorted to other circuits. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the ECM harness connectors. Turn the ignition on. While monitoring with the DRBIII®, connect a jumper wire between the (K23) APPS No. 1 signal circuit at the sensor harness connector and the (K852) APPS No. 1 5-volt supply circuit at the sensor harness connector. NOTE: With the sensor disconnected it is normal to have a APPS 1 and APPS 2 low voltage DTC set. Did DTC P2123 set? Yes --> Go To 24 No --> Replace and program the ECM in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Reconnect the APPS harness connector. Monitor the APPS 1 and APPS 2 voltage with the DRBIII® while depressing the throttle pedal. Is the voltage transition shown on the DRBIII® smooth while depressing the throttle and is the volta Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). No --> Replace the APPS. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

P1652 J1850 SHORT TO GROUND When Monitored and Set Condition: When Monitored: While the ignition is on. Set Condition: The ECM detects a short to ground on the J1850. POSSIBLE CAUSES ECM (D25) J1850 SHORTED COMMUNICATION DIAGNOSTIC PROCEDURE Turn the ignition off. Disconnect the ECM harness connectors. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between the (D25) J1850 circuit in the ECM harness connector and battery negative. Is the resistance less than 10 Ohms? Yes --> Go To 2 No --> Replace the ECM. Measure the resistance between the (D25) J1850 circuit and all other circuits in both ECM connectors. Is the resistance greater than 100k ohms? Yes --> Refer to the Body Diagnostic under Communications. No --> Repair (D25) J1850 shorted to another circuit.

P0839 4WD MODE SENSOR HIGH When Monitored and Set Condition: When Monitored: Continuously with the ignition key on. Set Condition: When the 4WD Mode Sensor input circuit voltage raises above 4.78 volts for 5.72 seconds. POSSIBLE CAUSES TRANSFER CASE POSITION SENSOR INPUT CIRCUIT OPEN TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO VOLTAGE TRANSFER CASE POSITION SENSOR POWERTRAIN/ENGINE CONTROL MODULE INTERMITTENT OPERATION DIAGNOSTIC PROCEDURE With the DRBIII(R), record and erase DTC's. Start the engine and cycle the Transfer Case through all positions. With the DRBIII(R), read Transfer Case DTCs. Is the Good Trip Counter equal to zero? Yes --> Go To 2 No --> Go To 6 Turn the ignition off to the lock position. Disconnect the Powertrain/Engine Control Module harness connectors. CAUTION: IF EQUIPPED WITH NGC CONTROLLER, DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Disconnect the Transfer Case Position Sensor harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the Transfer Case Position Sensor Input circuit. Is the resistance above 5.0 ohms? Yes --> Repair the Transfer Case Position Sensor input circuit for an open. No --> Go To 3 Turn the ignition on. Measure the voltage of the Transfer Case Position Sensor Input circuit. Is there any voltage present? Yes --> Repair the Transfer Case Position Sensor input circuit for a short to voltage. No --> Go To 4 Turn the ignition off to the lock position. Measure the resistance between the Transfer Case Position Sensor Input circuit and the Sensor Return circuit in the PCM/ECM harness connector. Is the resistance between 55 ohms and 1.3k ohms? Yes --> Go To 5 No --> Replace the Transfer Case Position Sensor. If there are no possible causes remaining, view repair. Repair Replace and program the Powertrain/Engine Control Module. Refer to ELECTRONIC CONTROL MODULES . Perform the appropriate Powertrain verification test. The conditions to set this DTC are not present at this time. NOTE: Use the Freeze Frame Data to help duplicate the conditions that set the DTC. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load. NOTE: Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. NOTE: Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. NOTE: Refer to any technical service bulletins that may apply. Were there any problems found? Yes --> Repair as necessary. No --> Test Complete.

P0838 4WD MODE SENSOR LOW When Monitored and Set Condition: When Monitored: Continuously with the ignition key on. Set Condition: When the 4WD Mode Sensor input circuit voltage falls below 0.3 volts for 5.72 seconds. POSSIBLE CAUSES TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO GROUND TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO SENSOR RETURN CIRCUIT TRANSFER CASE POSITION SENSOR POWERTRAIN/ENGINE CONTROL MODULE INTERMITTENT OPERATION DIAGNOSTIC PROCEDURE With the DRBIII(R), record and erase DTC's. Start the engine and cycle the Transfer Case through all positions. With the DRBIII(R), read Transfer Case DTCs. Is the Good Trip Counter equal to zero? Yes --> Go To 2 No --> Go To 6 Turn the ignition off to the lock position. Disconnect the Powertrain Control Module harness connector. CAUTION: IF EQUIPPED WITH NGC CONTROLLER, DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WELL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Disconnect the Transfer Case Position Sensor harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance between ground and the Transfer Case Position Sensor Input circuit. Is the resistance below 5.0 ohms? Yes --> Repair the Transfer Case Position Sensor input circuit for a short to ground. No --> Go To 3 Measure the resistance between the Transfer Case Position Sensor Input circuit and the Sensor Return circuit in the PCM/ECM harness connector. Is the resistance above 1000.0 ohms? Yes --> Go To 4 No --> Repair the Transfer Case Position Sensor Input circuit for a short to the Sensor Return circuit. Measure the resistance between the Transfer Case Position Sensor Input circuit and the Sensor Return circuit in the PCM/ECM harness connector. Is the resistance between 55 ohms and 1.3k ohms? Yes --> Go To 5 No --> Replace the Transfer Case Position Sensor. If there are no possible causes remaining, view repair. Repair Replace and program the Powertrain/Engine Control Module. Refer to ELECTRONIC CONTROL MODULES . Perform the appropriate Powertrain verification test. The conditions to set this DTC are not present at this time. NOTE: Use the Freeze Frame Data to help duplicate the conditions that set the DTC. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load. NOTE: Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. NOTE: Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. NOTE: Refer to any technical service bulletins that may apply. Were there any problems found? Yes --> Repair as necessary. No --> Test Complete.

P0837 4WD MUX SWITCH PERFORMANCE When Monitored and Set Condition: When Monitored: Continuously with the ignition on. Set Condition: The 4WD muxed switch input detected in an invalid range or irrational switch state. POSSIBLE CAUSES RELATED DTCS PRESENT TRANSFER CASE SHIFTER OUT OF ADJUSTMENT TRANSFER CASE POSITION SENSOR OUT OF TOLERANCE POWERTRAIN/ENGINE CONTROL MODULE DIAGNOSTIC PROCEDURE With the DRBIII(R), read DTCs. Are any other Transfer Case DTCs present? Yes --> Repair all other Transfer Case DTCs before proceeding. No --> Go To 2 Verify proper Transfer Case Shifter adjustment. Refer to appropriate TRANSFER CASE article. Is the Transfer Case Shifter adjusted correctly? Yes --> Go To 3 No --> Adjust the Transfer Case shifter linkage. Turn the ignition off to the lock position. Disconnect the PCM/ECM harness connector(s). CAUTION: IF EQUIPPED WITH NGC CONTROLLER, DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WELL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Measure the resistance across the Transfer Case Position Sensor signal circuit and Sensor Ground circuit at the PCM/ECM harness connector. Place the transfer case in each of the following positions: 2H - resistance should be between 1124 and 1243 ohms. 4H - resistance should be between 650 and 719 ohms. N - resistance should be between 389 and 431 ohms. 4L - resistance should be between 199 and 221 ohms. Were all resistance values in each transfer case position within the specified range? Yes --> Go To 4 No --> Replace the Transfer Case Position Sensor. If there are no possible causes remaining, view repair. Repair Replace and program the Powertrain/Engine Control Module. Refer to ELECTRONIC CONTROL MODULES . Perform the appropriate Powertrain verification test.

P0836 4WD MUX SWITCH STUCK When Monitored and Set Condition: When Monitored: When Transfer Case in 4WD Low. Set Condition: Four wheel drive (4WD) muxed switch input detected below minimum or above maximum acceptable voltage. POSSIBLE CAUSES TRANSFER CASE POSITION SENSOR INPUT CIRCUIT OPEN TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO GROUND TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO VOLTAGE TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORT TO SENSOR RETURN CIRCUIT TRANSFER CASE POSITION SENSOR POWERTRAIN/ENGINE CONTROL MODULE INTERMITTENT OPERATION DIAGNOSTIC PROCEDURE With the DRBIII(R), record and erase DTC's. Start the engine and cycle the Transfer Case through all positions. With the DRBIII(R), read Transfer Case DTCs. Is the Good Trip Counter equal to zero? Yes --> Go To 2 No --> Go To 8 Turn the ignition off to the lock position. Disconnect the Powertrain Control Module harness connector. CAUTION: IF EQUIPPED WITH NGC CONTROLLER, DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WELL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Disconnect the Transfer Case Position Sensor harness connector. NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the Transfer Case Position Sensor Input circuit. Is the resistance above 5.0 ohms? Yes --> Repair the Transfer Case Position Sensor input circuit for an open. No --> Go To 3 Measure the resistance between ground and the Transfer Case Position Sensor Input circuit. Is the resistance below 5.0 ohms? Yes --> Repair the Transfer Case Position Sensor input circuit for a short to ground. No --> Go To 4 Turn the ignition on. Measure the voltage of the Transfer Case Position Sensor Input circuit. Is there any voltage present? Yes --> Repair the Transfer Case Position Sensor input circuit for a short to voltage. No --> Go To 5. Turn the ignition off to the lock position. Measure the resistance between the Transfer Case Position Sensor Input circuit and the Sensor Return circuit in the PCM harness connector. Is the resistance above 1000.0 ohms? Yes --> Go To 6 No --> Repair the Transfer Case Position Sensor Input circuit for a short to the Sensor Return circuit. Measure the resistance between the Transfer Case Position Sensor Input circuit and the Sensor Return circuit in the PCM harness connector. Is the resistance between 55 ohms and 1.3k ohms? Yes --> Go To 7 No --> Replace the Transfer Case Position Sensor. If there are no possible causes remaining, view repair. Repair Replace and program the Powertrain/Engine Control Module. Refer to ELECTRONIC CONTROL MODULES . Perform the appropriate Powertrain verification test. The conditions to set this DTC are not present at this time. NOTE: Use the Freeze Frame Data to help duplicate the conditions that set the DTC. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load. NOTE: Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. NOTE: Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. NOTE: Refer to any technical service bulletins that may apply. Were there any problems found? Yes --> Repair as necessary. No --> Test Complete.

P0733 GEAR RATIO ERROR IN 3RD When Monitored and Set Condition: When Monitored: The transmission gear ratio is monitored continuously while the transmission is in gear. Set Condition: If the ratio of the Input RPM to the Output RPM does not match the current gear ratio. This DTC can take up to five minutes of problem identification before illuminating the MIL. POSSIBLE CAUSES RELATED DTC'S PRESENT RELATED PRESSURE SWITCH DTC'S PRESENT INTERNAL TRANSMISSION TRANSMISSION SOLENOID/TRS ASSEMBLY INTERMITTENT GEAR RATIO ERRORS DIAGNOSTIC PROCEDURE NOTE: Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level. Refer to appropriate AUTOMATIC TRANSMISSION article. NOTE: Always perform diagnostics with a fully charged battery to avoid false symptoms. NOTE: Diagnose 1 Trip Failures as a fully matured DTC. NOTE: Verify flash level of Powertrain Controller. Some problems are corrected by software upgrades to the Transmission and Engine Systems. NOTE: Due to the integration of the Powertrain and Transmission control modules - if a controller flash is performed it is necessary to perform STANDARD PROCEDURE - TCM QUICK LEARN and the STANDARD PROCEDURE - DRIVE LEARN . Failure to do so may result in shift quality complaints. NOTE: Check for applicable TSB's that may apply. With the DRBIII(R), read the engine DTC's. Check and repair all Engine DTC's prior to performing Transmission symptom diagnostics. With the DRBIII(R), read Transmission DTC's. Record all DTC's and 1 Trip Failures. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary. Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test for SYMPTOM: P0706-CHECK SHIFTER SIGNAL . For Gear Ratio DTC's, check and record all CVI's. Most DTC's set on start up but some must be set by driving the vehicle to ensure that all diagnostic monitors have run. Perform this procedure prior to Symptom diagnosis. Continue Go To 2 With the DRBIII(R), check for other transmission DTCs If any of these DTCs are present, perform their respective tests first. Are the DTCs P0944, P0715, P0720, P1794, P0867, P0932, P0868, or P0869 present also? Yes --> Refer to the Transmission Category and perform the appropriate symptom. If any of these DTCs are present, they will cause a Speed Ratio Error. Perform the test for P0944 first if it is present. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 3 With the DRBIII(R), check for other transmission DTCs Are the DTCs P0870 OD Hydraulic Pressure Switch and/or P0871 OD Pressure Switch present also? Yes --> Replace the Transmission Solenoid/TRS Assembly. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 4 With the DRBIII(R), perform the 3rd Gear Clutch Test. Follow the instructions on the DRBIII(R). Increase the throttle angle, TPS Degree, to 30° for no more than a few seconds. CAUTION: Do not overheat the transmission. Did the clutch test pass, Input speed remain at zero? Yes --> Go To 5 No --> Go To 6 The conditions to set this DTC are not currently present. Check the gearshift linkage adjustment. Intermittent gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit. Remove the Starter Relay. NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition. Install Transmission Simulator, Miller tool #8333. Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator. Gear ratio DTCs can also be set under extreme temperature conditions, this is usually caused by an internal problem. Verify if the problem is only experienced under extreme hot or cold conditions. With the DRBIII(R), check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set. Were there any problems found. Yes --> Repair as necessary. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Test Complete. Repair the transmission as necessary. If there were any line pressure DTC's also present, make sure to inspect the Transmission Oil Pump and Pressure Control Solenoid. Refer to appropriate AUTOMATIC TRANSMISSION article. NOTE: If DTC's P0871 and/or P0870 are also present, replace the Transmission Solenoid/TRS Assembly in addition to necessary internal repairs. If there are no possible causes remaining, view repair. Repair Repair internal transmission. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 :

P0732 GEAR RATIO ERROR IN 2ND When Monitored and Set Condition: When Monitored: The transmission gear ratio is monitored continuously while the transmission is in gear. Set Condition: If the ratio of the Input RPM to the Output RPM does not match the current gear ratio. This DTC can take up to five minutes of problem identification before illuminating the MIL. POSSIBLE CAUSES RELATED DTC'S PRESENT CHECK 2C AND UD CLUTCH EXTRA #7 CHECK BALL IN POCKET OR PASSAGE INTERNAL TRANSMISSION TRANSMISSION SOLENOID/TRS ASSEMBLY INTERMITTENT GEAR RATIO ERRORS TEST DIAGNOSTIC PROCEDURE NOTE: Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level. Refer to appropriate AUTOMATIC TRANSMISSION article. NOTE: Always perform diagnostics with a fully charged battery to avoid false symptoms. NOTE: Diagnose 1 Trip Failures as a fully matured DTC. NOTE: Verify flash level of Powertrain Controller. Some problems are corrected by software upgrades to the Transmission and Engine Systems. NOTE: Due to the integration of the Powertrain and Transmission control modules - if a controller flash is performed it is necessary to perform STANDARD PROCEDURE - TCM QUICK LEARN and the STANDARD PROCEDURE - DRIVE LEARN . Failure to do so may result in shift quality complaints. NOTE: Check for applicable TSB's that may apply. With the DRBIII(R), read the engine DTC's. Check and repair all Engine DTC's prior to performing Transmission symptom diagnostics. With the DRBIII(R), read Transmission DTC's. Record all DTC's and 1 Trip Failures. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary. Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test for SYMPTOM: P0706-CHECK SHIFTER SIGNAL . For Gear Ratio DTC's, check and record all CVI's. Most DTC's set on start up but some must be set by driving the vehicle to ensure that all diagnostic monitors have run. Perform this procedure prior to Symptom diagnosis. Continue Go To 2 With the DRBIII(R), check Transmission DTCs Are there any Loss of Prime, Speed Sensor, and/or Line Pressure DTCs present? Yes --> Refer to the Transmission Category and perform the appropriate symptom. If any of these DTCs are present, they may cause a Speed Ratio Error. Perform the test procedure for P0944-LOSS OF PRIME first if it is present. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 3 With the DRBIII(R), check Transmission DTCs Is the DTC P0845 and/or P0846 also present? Yes --> Replace the Transmission Solenoid/TRS Assembly. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 4 With the DRBIII(R), record the EATX DTC EVENT DATA for P0732. Does the EATX DTC EVENT DATA show a Input speed of 0? Yes --> Go To 5 No --> Go To 6 The conditions to set this DTC are not currently present. Check the gearshift linkage adjustment. Intermittent gear ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit. Remove the Starter Relay. NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition. Install Transmission Simulator, Miller tool # 8333. Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator. Gear ratio DTCs can also be set under extreme temperature conditions, this is usually caused by an internal problem. Verify if the problem is only experienced under extreme hot or cold conditions. With the DRBIII(R), check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set. Were there any problems found? Yes --> Repair as necessary. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Test Complete. Remove the Valve Body and air check the 2C and UD clutches. Refer to appropriate AUTOMATIC TRANSMISSION article. Do the 2C and UD clutches pass the air test? Yes --> Go To 7 No --> Repair internal transmission. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . Check the #7 Check Ball pocket and passage for an extra check ball. Is there an extra check ball in the #7 Check Ball pocket or passage? Yes --> Remove extra #7 Check Ball. Make sure the check ball to be used is not cut or damaged and repair as necessary. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 8 Repair internal transmission as necessary. Refer to the appropriate OVERHAUL article. If there are no possible causes remaining, view repair. Repair Repair internal transmission. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1

P0731 GEAR RATIO ERROR IN 1ST When Monitored and Set Condition: When Monitored: The transmission gear ratio is monitored continuously while the transmission is in gear. Set Condition: If the ratio of the Input RPM to the Output RPM does not match the current gear ratio. This DTC can take up to five minutes of problem identification before illuminating the MIL. POSSIBLE CAUSES RELATED DTC'S PRESENT INTERNAL TRANSMISSION INTERMITTENT GEAR RATIO ERRORS DIAGNOSTIC PROCEDURE NOTE: Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level. Refer to appropriate AUTOMATIC TRANSMISSION article. NOTE: Always perform diagnostics with a fully charged battery to avoid false symptoms. NOTE: Diagnose 1 Trip Failures as a fully matured DTC. NOTE: Verify flash level of Powertrain Controller. Some problems are corrected by software upgrades to the Transmission and Engine Systems. NOTE: Due to the integration of the Powertrain and Transmission control modules - if a controller flash is performed it is necessary to perform STANDARD PROCEDURE - TCM QUICK LEARN and the STANDARD PROCEDURE - DRIVE LEARN . Failure to do so may result in shift quality complaints. NOTE: Check for applicable TSB's that may apply. With the DRBIII(R), read the engine DTC's. Check and repair all Engine DTC's prior to performing Transmission symptom diagnostics. With the DRBIII(R), read Transmission DTC's. Record all DTC's and 1 Trip Failures. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary. Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test for SYMPTOM: P0706-CHECK SHIFTER SIGNAL . For Gear Ratio DTC's, check and record all CVI's. Most DTC's set on start up but some must be set by driving the vehicle to ensure that all diagnostic monitors have run. Perform this procedure prior to Symptom diagnosis. Continue Go To 2 With the DRBIII(R), check for other transmission DTCs If any of these DTCs are present, perform their respective tests first. Are DTCs P0944, P0715, P0720, P1794, P0867, P0932, P0868, or P0869 present also? Yes --> Refer to the Transmission Category and perform the appropriate symptom. If any of these DTCs are present, they may cause a Speed Ratio Error. Perform the test for P0944 first if it is present. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 3 With the DRBIII(R), perform the 1st Gear Clutch Test. Follow the instructions on the DRBIII(R). Increase the throttle angle or TPS Degree to 30° for no more than a few seconds. CAUTION: Do not overheat the transmission. Did the Clutch Test pass, Input Speed remain at zero? Yes --> Go To 4 No --> Go To 5 The conditions to set this DTC are not currently present. With the DRBIII(R), check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set. If the DTC Event Data shows fault P0731 was set in the Park, Reverse, or Neutral, replace the Powertrain Control Module. If the DTC Event Data shows fault P0731 set with input RPM = zero, check input speed sensor and related wiring. If the DTC Event Data shows fault P0731 set with line pressure significantly below Desired Line Pressure, check for cause of low line pressure (i.e., oil level, misinstalled or damages filter or filter seal, sticking main regulator valve in pump, etc.). If the DTC Event Data shows fault P0731 set with UD pressure switch open (but line pressure matches Desired Line Pressure), air check the UD clutch passage for leakage and if OK, replace the solenoid assembly.Check the gearshift linkage adjustment. Intermittent Gear Ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Sensor Ground circuit. Remove the Starter Relay from the PDC. NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition. Install Transmission Simulator, Miller tool # 8333. Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator. Gear ratio DTCs can also be set under extreme temperature conditions, this is usually caused by an internal problem. Verify if the problem is only experienced under extreme hot or cold conditions. Were there any problems found. Yes --> Repair as necessary. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 . No --> Test Complete. Repair internal transmission as necessary. Refer to the appropriate OVERHAUL article. If there were any line pressure DTC's present along with this DTC, make sure to inspect the Transmission Oil Pump and Pressure Control Solenoid. If DTC's P0876 and/or P0875 were present in addition to the P0731, replace the Transmission Solenoid/TRS Assembly in addition to necessary internal repairs. Pay particular attention to the following list of possible causes when repairing the transmission condition. Cut UD piston seal Failed overrunning clutch Faulty solenoid module Cut UD accumulator seal ring Broken UD accumulator piston Broken reaction shaft support seal ring Low line pressure Broken/missing main valve body bleed orifice Broke/missing dribbles orifice assy in reaction shafts support If there are no possible causes remaining, view repair. Repair Repair internal transmission. Refer to appropriate AUTOMATIC TRANSMISSION article. Perform (NGC) 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1 .