P007E
P007E-CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT INTERMITTENT/ERRATIC
For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.
The Air Cooler Temperature Sensor (CAC) and the Boost Pressure Sensor are combined in one sensor and are located near the EGR Airflow Throttle Control Valve. The Engine Control Module (ECM) provides a 5-volt reference voltage to the sensor. The ECM monitors the temperature of the air entering the intake using the CAC. At key on after an 8 hour cold soak, the CAC Temperature Sensor is compared to the Battery Temperature Sensor, Intake Temperature Sensor, and Coolant Temperature Sensor readings. If the temperatures differ more than a calibrated amount, a DTC is recorded. In the case that all four sensor values are distributed over a range of temperatures this diagnostic will not run. A block heater is one possible cause of such a condition. The key on monitor is disabled for ambient temperatures below 20°F. The rationality check looks at the temperature reading from the CAC Temperature Sensor over time and ensures that it changes. This monitor is used to verify the sensor is responding with temperature change. Both the key-on and rationality error require that the diagnostic fails in two consecutive drive cycles before the MIL lamp is lit. The ECM turns off the MIL lamp when the diagnostic runs and passes in 4 consecutive drive cycles.
- When Monitored:
Key on engine off and while engine is running.
- Set Condition:
At key on engine off, the CAC Temperature Sensor reads differently than the Battery Temperature and Ambient Air Temperature Sensors, or while the engine is running the Engine Control Module (ECM) does not read a change in value from the CAC Temperature Sensor over time.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
NOTE: If there are any 5-volt supply DTCs present, repair those DTCs before proceeding with this test.
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 30 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. Intermittent Condition Test.
2. CAC TEMPERATURE SENSOR
1. Let engine cold soak up to eight hours.
2. Turn the ignition on.
3. With the scan tool, monitor CAC Temperature Sensor, Battery Temperature Sensor, Intake Manifold Temperature Sensor, and Coolant Temperature Sensor.
NOTE: Ensure ambient air temperature is above -6.7°C (20°F) when performing this test.
NOTE: Ensure there is no external heat source, such as a block heater, operating during this test or within the 8 hour cold soak.
Does the CAC Temperature Sensor read differently from the other sensors?
Yes
- Replace the CAC Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Go To 3
3. CAC TEMPERATURE SENSOR
1. Turn the ignition off.
2. Disconnect the CAC Temperature Sensor harness connector.
3. Remove the CAC Temperature Sensor and reconnect the wiring to the sensor.
4. Turn the ignition on.
5. With the scan tool in Sensors, monitor the CAC Temperature Sensor while heating the sensor with an external heat source (DO NOT USE OPEN FLAME).
Does the reading from the sensor increase at least -15°C (5°F) on the scan tool?
Yes
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
No
- Replace the CAC Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.