P007C - Charge Air Cooler Temperature Sensor Circuit Low
Theory of Operation
The Charge Air Cooler Temperature Sensor circuit is represented as the Intake Manifold Temperature Sensor circuit on the Cab and Chassis. On the Regular Cab it is still called the Charge Air Cooler Temperature Sensor circuit. In both configurations, this DTC refers to the circuit that runs from the Powertrain Control Module (PCM) C1 harness connector / terminal 62 to the Temperature/Pressure MAP sensor / terminal 3. The Powertrain Control Module (PCM) supplies 5-Volts to the Charge Air Cooler Temperature signal circuit. The PCM monitors the change in voltage caused by changes in the resistance of the sensor to determine the Charge Air Cooler temperature. The PCM will illuminate the Malfunction Indicator Lamp (MIL) after the diagnostic runs and fails in two consecutive drive cycles. During this time the customer may notice periods of white smoke as well as the fan running more often. The MIL lamp is turned off once the diagnostic runs and passes in four consecutive drive cycles.
• When Monitored:
The PCM monitors the change in signal voltage and converts this to a temperature value.
• Set Condition:
The CAC Outlet Temperature Sensor Signal circuit goes below a calibrated threshold.
Possible Causes
CAC OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
CAC OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
TEMPERATURE/PRESSURE MAP SENSOR
POWERTRAIN CONTROL MODULE (PCM)
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
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 the DTC 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 (K48) CAC OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1.
2. Turn the ignition off.
3. Disconnect the Temperature/Pressure Map Sensor harness connector.
4. Disconnect the PCM C1 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
5. Measure the resistance between ground and the (K48) CAC Outlet Temperature Sensor Signal circuit at
the Temperature/Pressure MAP Sensor harness connector.
Is the resistance above 5.0 Ohms?
Yes
• Go To 3
No
• Repair the (K48) CAC Outlet Temperature Sensor 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).
3. CHECK THE (K48) CAC OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K48) CAC Outlet Temperature Sensor Signal circuit between the Temperature/Pressure Map Sensor harness connector and the PCM C1 harness connector. Is the resistance below 5.0 Ohms?
Yes
• Go To 4
No
• Repair the (K48) CAC Outlet Temperature Sensor 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. TEMPERATURE/PRESSURE MAP SENSOR
1. Replace the Temperature/Pressure MAP Sensor.(Refer to 14 - Fuel System/Fuel Injection/SENSOR,
TMAP-Intake Manifold/Removal)
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Start the vehicle. It may be necessary to drive vehicle to reset DTC.
6. With the scan tool, read DTCs.
Did the DTC return?
Yes
• Go To 5
No
• Repair is complete.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
5. POWERTRAIN CONTROL MODULE
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following
conditions:
• Proper connector installation.
• Damaged connector locks.
• Corrosion.
• Other signs of water intrusion.
• Weather seal damage (if equipped).
• Bent terminals.
• Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
• Terminals that have been pushed back into the connector cavity.
• Perform a terminal drag test on each connector terminal to verify proper terminal tension. Repair any conditions that are found.
5. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Freeze Frame and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read PCM DTCs.
Did the DTC return?
Yes
• Replace the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control/Removal) .
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Test complete.
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).