Mopar1973Man

P0087 - Fuel Rail Pressure Too Low Special Tools: Click to display a list of tools used in this procedure When Monitored and Set Conditions When Monitored: This diagnostic runs continuously when the following conditions are met: • With the engine running. Set Conditions: • The Powertrain Control Module (PCM) detects that the actual fuel pressure reading is below a calibrated threshold. This DTC will cause active regeneration to be disabled. Default Actions: • The MIL is illuminated. Possible Causes P000F PRESENT EXTERNAL FUEL LEAKS GELLED FUEL NO VOLTAGE AT CHASSIS MOUNTED FUEL HEATER NO VOLTAGE AT ENGINE MOUNTED FUEL HEATER CHASSIS MOUNTED FUEL HEATER-FUEL FILTER ENGINE MOUNTED FUEL HEATER-FUEL FILTER HIGH PRESSURE PUMP INJECTOR LEAKAGE IN TANK LIFT PUMP FUEL PRESSURE LIMITING VALVE Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 1. P000F PRESENT 1. Ignition on, engine not running. 2. With the scan tool, read DTCs. Is DTC P000F active? Yes • Perform the Diagnostics for DTC P000F first. • If DTC P0087 is still active or pending after the P000F Diagnostics is completed, begin this Diagnostic Tree again. No • Go To 2 2. CHECK FOR OTHER DTCS 1. With the scan tool, read DTCs. Are any other injector/fuel pressure related DTCs present? Yes • Troubleshoot other injector/fuel pressure related DTCs first. No • Go To 3 3. CHECK FOR EXTERNAL FUEL LEAKS 1. Put on personal protective equipment. 2. Operate engine at idle when looking for fuel leaks. 3. Use the scan tool to operate engine at a variety of engine speeds. Any external leaks detected? Yes • Repair or replace component with external fuel leak. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Go To 4 4. CHECK OPERATING CONDITIONS 1. Determine the environmental conditions at or near the time the DTC set. Has the vehicle been operated or cold soaked in ambient temperatures below freezing? Yes • Go To 5 No • Go To 7 5. CHECK FOR GELLED FUEL/PERFORM THE IN-TANK LIFT PUMP FLOW TEST NOTE: Before performing the IN-TANK FUEL LIFT PUMP FLOW test, verify that the fuel level in the fuel tank is above 1/4 full. If fuel tank is not above 1/4 full the pump will take in air causing the test results to be inaccurate. 1. Disconnect the low pressure fuel supply line from the High Pressure Fuel Pump. Connect the Decay Tool, Fuel 8978A to the low pressure fuel supply line. WARNING: To reduce the risk of fire and serious possible serious or fatal injury, place the Reservoir Assembly 534960 (3) on the floor and out of the way so that it is not a trip hazard. 2. Perform the following to purge air from the system: • With the scan tool, actuate the In-Tank Fuel Lift Pump Module. • Open the Flow Test Valve and allow the fuel to flow into the Reservoir for 10 seconds, then close the Flow Test Valve. • Turn the ignition off. • Disconnect, empty, and then reconnect the Reservoir Assembly. 3. Perform the following three times to find the average flow rate: • With the scan tool, actuate the In-Tank Fuel Lift Pump Module. • Open the Flow Test Valve (1) for 10 seconds, then close the Valve. • Turn the ignition off. • Measure and record the amount of fuel in the Reservoir Assembly. • Disconnect, empty, and then reconnect the Reservoir Assembly. 4. Add the three recorded measurements and then divide the total by three to calculate the average flow rate. NOTE: The flow rate specification is 500 ml in 10 seconds. Does the average flow rate meet or exceed the specification? Yes • If the vehicle exhibited symptoms related to fuel gelling such as hard start, start and stall, and/or low power, but no longer exhibits these symptoms, fuel gelling may have been present but corrected itself. The fuel temperature may have increased through normal operation or if the vehicle was parked inside a warm building. Verify both fuel heaters are receiving power with the ignition on, and also check for proper operation of the fuel heaters. (Refer to 14 - Fuel System/Fuel Delivery, 6.7L Diesel/HEATER, Fuel/Diagnosis and Testing) . • Then, Go To 7 No • Leave the Fuel Decay Tester installed. Remove both fuel filters and inspect for fuel gelling/wax build-up and other contaminants. If wax build-up is found, the fuel has gelled. Replace both fuel filters and correct the fuel gelling accordingly before any further testing. Verify both fuel heaters are receiving power with the ignition on, and also check for proper operation of the fuel heaters. (Refer to 14 - Fuel System/Fuel Delivery, 6.7L Diesel/HEATER, Fuel/Diagnosis and Testing) . • If no wax build-up or signs of fuel gelling is found, replace both Fuel Filter/Water Separators in accordance with the Service Information. • Then, Go To 6 6. RECHECK IN-TANK FUEL LIFT PUMP FLOW 1. Perform the following to purge air from the system: • With the scan tool, actuate the In-Tank Fuel Lift Pump Module. • Open the Flow Test Valve for 10 seconds, then close the Valve. • Turn the ignition off. • Disconnect, empty, and then reconnect the Reservoir Assembly. 2. Perform the following three times to find the average flow rate: • With the scan tool, actuate the In-Tank Fuel Lift Pump Module. • Open the Flow Test Valve for 10 seconds, then close the valve. • Turn the ignition off. • Measure and record the amount of fuel in the Reservoir Assembly. • Disconnect, empty, and then reconnect the Reservoir Assembly. 3. Add the three recorded measurements and then divide the total by three to calculate the average flow rate. NOTE: The flow rate specification is 500 ml in 10 seconds. Does the average flow rate meet or exceed the specification? Yes • Repair complete. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Use the wiring diagram as a guide to check the In-Tank Fuel Lift Pump wiring for an open, high resistance, or short to ground. If the In-Tank Fuel Lift Pump wiring is okay, remove the fuel tank and replace the In-Tank Fuel Lift Pump Module in accordance with the Service Information. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 7. CHECK THE FUEL DELIVERY SYSTEM 1. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) and perform the CHECKING THE FUEL DELIVERY SYSTEM diagnostic procedure. Were any problems found? Yes • Repair as necessary. No • Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P008A - Low Fuel Pressure Fuel System Pressure - Too Low When Monitored and Set Conditions When Monitored: This diagnostic runs continuously when the following conditions are met: • With the engine running. Set Conditions: • The Powertrain Control Module (PCM) detects that the Low Pressure Fuel Delivery pressure is below a calibrated value for a calibrated amount of time. Default Actions: • The MIL is illuminated. Possible Causes HIGH PRESSURE FUEL DELIVERY LOW PRESSURE FUEL DELIVERY Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). Diagnostic Test 1. OTHER DTCS 1. Ignition on, engine not running. 2. With the scan tool, read DTCs. Are there any other DTCs related to Fuel Pressure? Yes • Perform the diagnostics for those DTCs before proceeding with this one. No • Go To 2 2. ACTIVE DTC 1. With the scan tool, record all Freeze frame data. 2. With the scan tool, erase DTCs. 3. Turn the ignition off for 75 seconds. 4. Turn the ignition on. 5. With the scan tool, read DTCs. Did DTC P008A reset? Yes • Go To 3 No • Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 3. CHECK THE FUEL DELIVERY SYSTEM 1. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) and perform the CHECKING THE FUEL DELIVERY SYSTEM diagnostic procedure. Were any problems found? Yes • Repairs are complete. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0073 - Ambient Air Temperature Sensor Circuit High Theory of Operation The Ambient Air Temperature (AAT) Sensor is located in the driver's door mirror. The Driver's Door Module (DDM) receives the data from the AAT sensor and sends it to the Body Control Module (BCM). The BCM then passes the data on to the Powertrain Control Module (PCM). There are two rationality tests. The first test is: Ignition on/engine running. The second test is: After an eight hour cold soak, at key on the readings for the AAT, Charge Air Cooler (CAC) temperature (D2, DJ), Intake Manifold Temperature (DD, DP), and the Engine Coolant Temperature (ECT) Sensors are all compared. If the temperatures differ by more than a calibrated amount, then the appropriate sensor fault code would be recorded. The PCM rationality check looks at the temperature reading from the sensor over time and ensures that it changes with the engine running. If the sensor reading does not change over a calibrated time limit, the fault will be recorded. When Monitored and Set Conditions When Monitored: This diagnostic runs continuously when the following conditions are met: • With the ignition on. Set Conditions: • The Powertrain Control Module (PCM) detects that the Ambient Air Temperature (AAT) Signal circuit value is above a calibrated threshold. Default Actions: • The MIL is illuminated. Possible Causes AAT SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE AAT SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE DRIVER MIRROR HEATER RETURN CIRCUIT OPEN/HIGH RESISTANCE AMBIENT AIR TEMPERATURE (AAT) SENSOR Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). Diagnostic Test 1. ACTIVE DTC NOTE: There is no direct circuit input from the Ambient Air Temperature Sensor to the PCM. If there are any Loss of Communication DTCs related to the DDM present in the Body Control Module or elsewhere, perform those diagnostics before continuing with this diagnostic tree. NOTE: If there are any other DTCs related to the Ambient Air Temperature Sensor present in the BCM, DDM, or any other module, perform those diagnostics before continuing with this diagnostic tree. 1. Turn the ignition on. 2. With the scan tool, record all Freeze frame data. 3. With the scan tool, erase DTCs. 4. Turn the ignition off for 75 seconds. 5. Turn the ignition on. 6. With the scan tool, read DTCs. Did DTC P073 reset? Yes • Go To 2 No • Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 2. CHECK THE (G31) AAT SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 1. Disconnect the AAT Sensor harness connector. 2. Measure the voltage of the (G31) AAT Signal circuit at the AAT Sensor harness connector. NOTE: The voltage should read approximately 5.0 Volts with connector disconnected and key on. Is the voltage above 5.2 Volts? Yes • Repair the (G31) Ambient Air Temperature Signal circuit for a short to voltage. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Go To 3 3. CHECK THE (G31) AAT SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 1. Disconnect the DDM harness connector. 2. Measure the resistance of the (G31) AAT Signal circuit between the AAT Sensor harness connector and the DDM harness connector. Is the resistance below 5.0 Ohms? Yes • Go To 4 No • Repair the (G31) Ambient Air Temperature Signal circuit for an open or high resistance. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 4. CHECK THE (C160) DRIVER MIRROR HEATER RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 1. 2. Measure the resistance of the (C160) Driver Mirror Heater Return circuit between the ECT Sensor harness connector and the PCM C1 harness connector. Is the resistance below 5.0 Ohms? Yes • Replace the Ambient Air Temperature Sensor in accordance with the Service Information.(Refer to 24 - Heating and Air Conditioning/Controls/SENSOR, Ambient Temperature/Removal) • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Repair the (C160) Driver Mirror Heater Return circuit for an open or high resistance. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0072 - Ambient Air Temperature Sensor Circuit Low Theory of Operation The Ambient Air Temperature (AAT) Sensor is located in the driver's door mirror. The Driver's Door Module (DDM) receives the data from the AAT sensor and sends it to the Body Control Module (BCM). The BCM then passes the data on to the Powertrain Control Module (PCM). There are two rationality tests. The first test is: Ignition on/engine running. The second test is: After an eight hour cold soak, at key on the readings for the AAT, Charge Air Cooler (CAC) temperature (D2, DJ), Intake Manifold Temperature (DD, DP), and the Engine Coolant Temperature (ECT) Sensors are all compared. If the temperatures differ by more than a calibrated amount, then the appropriate sensor fault code would be recorded. The PCM rationality check looks at the temperature reading from the sensor over time and ensures that it changes with the engine running. If the sensor reading does not change over a calibrated time limit, the fault will be recorded. When Monitored and Set Conditions When Monitored: This diagnostic runs continuously when the following conditions are met: • With the ignition on. Set Conditions: • The Powertrain Control Module (PCM) detects that the Ambient Air Temperature (AAT) Signal circuit has fallen below a calibrated threshold. Default Actions: • The MIL is illuminated. Possible Causes AAT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND AAT SENSOR SIGNAL CIRCUIT SHORTED TO DRIVER MIRROR HEATER RETURN CIRCUIT AMBIENT AIR TEMPERATURE (AAT) SENSOR Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). Diagnostic Test 1. ACTIVE DTC NOTE: There is no direct circuit input from the Ambient Air Temperature Sensor to the PCM. NOTE: If there are any Loss of Communication DTCs related to the DDM present in the Body Control Module or elsewhere, perform those diagnostics before continuing with this diagnostic tree. NOTE: If there are any other DTCs related to the Ambient Air Temperature Sensor present in the BCM, DDM, or any other module, perform those diagnostics before continuing with this diagnostic tree. 1. Turn the ignition on. 2. With the scan tool, record all Freeze frame data. 3. With the scan tool, erase DTCs. 4. Turn the ignition off for 75 seconds. 5. Turn the ignition on. 6. With the scan tool, read DTCs. Did DTC P072 reset? Yes • Go To 2 No • Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 2. CHECK THE (G31) AAT SIGNAL CIRCUIT FOR A SHORT TO GROUND 1. Turn the ignition off. 2. Disconnect the AAT Sensor harness connector. NOTE: Check connectors - Clean/repair as necessary. 3. Measure the resistance between ground and the (G31) AAT Signal circuit. Is the resistance below 10k Ohms? Yes • Repair the (G31) AAT Signal circuit for a short to ground. • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Go To 3 3. CHECK FOR THE (G31) AAT SIGNAL CIRCUIT SHORTED TO THE (C160) DRIVER MIRROR HEATER RETURN CIRCUIT 1. Disconnect the Driver Door Module. 2. Measure the resistance between the (G31) AAT Signal circuit and the (C160) Driver Mirror Heater Return circuit at the AAT Sensor harness connector. Is the resistance below 10k Ohms? Yes • Repair the short between the ((G31) AAT Signal circuit and the (C160) Driver Mirror Heater Return circuit. • Perform POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). No • Replace the Ambient Air Temperature Sensor in accordance with the Service Information.(Refer to 24 - Heating and Air Conditioning/Controls/SENSOR, Ambient Temperature/Removal) • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).