P007B

P007B-CHARGE AIR COOLER TEMPERATURE SENSOR CIRCUIT PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Charge 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 Powertrain Control Module (PCM) provides a 5-Volt reference voltage to the sensor. The PCM monitors the temperature of the air entering the intake using the CAC Temperature Sensor. At key-on after an eight hour cold soak, the CAC Temperature Sensor is compared to the EGR Orifice 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 errors require that the diagnostic fails in two consecutive drive cycles before the MIL lamp is lit. The PCM turns off the MIL lamp when the diagnostic runs and passes in four 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 EGR Orifice Temperature Sensor and Coolant Temperature Sensor, or while the engine is running the Powertrain Control Module (PCM) 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 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC return?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE AIR CLEANER BOX FOR PROPER SEALING
1. Check the connection between the Inlet Air Tube and the Air Cleaner Box to make sure that it is sealed properly.

Is the Air Cleaner Box to Inlet Air Tube installed and sealed properly?

Yes

- Go To 3

No

- Repair the connection between the Air Cleaner Box and the Inlet Air Tube.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

3. CHECK THE CHARGE AIR COOLER AND SYSTEM FOR DIRT OR DEBRIS
1. Remove the hoses at the Charge Air Cooler and Turbo outlet and inspect the system for signs of excessive oil, dirt or debris.

Does the Charge Air Cooling system show signs of excessive dirt or debris?

Yes

- Clean the Charge Air Cooling system.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. CHECK THE 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, EGR Orifice Temperature Sensor and Coolant Temperature Sensor.

NOTE: Make sure ambient air temperature is above -6.7°C (20°F) when performing this test.

NOTE: Make sure 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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. 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 5°F on the scan tool?

Yes

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the CAC Temperature Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.