Diagnostic Test
- CHECK FOR AN ACTIVE DTC NOTE:
Diagnose and repair any engine overheating concerns before continuing with this test procedure.
- CHECK FOR HIGH RESISTANCE IN THE (K932) EGR TEMPERATURE SENSOR SIGNAL CIRCUIT
- Turn the ignition off.
- Disconnect the EGR Temperature Sensor harness connector.
- Disconnect the PCM C2 harness connector.CAUTION:
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 the GPEC Diagnostic Adaptor to perform the diagnosis.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Measure the resistance of the (K932) EGR Temperature Sensor Signal circuit between the EGR Temperature Sensor harness connector to the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 3
No
- Repair the (K932) EGR Temperature Sensor Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK FOR HIGH RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
- Measure the resistance of the (K900) Sensor ground circuit between the EGR Temperature Sensor harness connector to the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 4
No
- Repair the (K900) Sensor ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance of the (K900) Sensor ground circuit between the EGR Temperature Sensor harness connector to the GPEC Adaptor.
- CHECK THE EGR COOLER AND HOSES FOR AN EXTERNAL LEAK
- Pressure test the cooling system and inspect the EGR Cooler Assembly and hoses for signs of a coolant leak.
Were any leaks found?
Yes
- Repair the leak by repairing or replacing the leaking hoses or EGR Cooler Assembly in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 5
- Pressure test the cooling system and inspect the EGR Cooler Assembly and hoses for signs of a coolant leak.
- CHECK THE EGR COOLER FOR AN INTERNAL LEAK
- Inspect the inside of the exhaust tailpipe for the presence of engine coolant.NOTE:
A severe leak may also be identified by excessive white smoke from the tailpipe with the engine running resembling the signs of a faulty cylinder head gasket. Before condemning a cylinder head gasket, make sure to inspect for coolant inside the EGR Tube.
- If no coolant was found in the tailpipe, disconnect the EGR Tube that connects between the EGR Valve and the Intake Manifold and inspect the inside of the EGR Tube for the presence of engine coolant.
Was coolant found inside the exhaust tailpipe or EGR Tube?
Yes
- Replace the EGR Cooler Assembly in accordance with the Service Information. Refer to COOLER, EXHAUST GAS RECIRCULATION (EGR), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 6
- Inspect the inside of the exhaust tailpipe for the presence of engine coolant.
- CHECK THE EGR TEMPERATURE SENSOR
- Replace the EGR Temperature Sensor in accordance with the Service Information. Refer to SENSOR, EGR TEMPERATURE, REMOVAL .
- Reconnect the EGR Tube.
- Reconnect the PCM C2 harness connector.
- Reconnect the EGR Temperature Sensor harness connector.
- Start the engine and allow it to reach operating temperature.
- With the scan tool, read the EGR Temperature Sensor reading.NOTE:
Normally, the sensor should read approximately 75°C (167°F) when the engine is idling at normal operating temperature.
Is the EGR Temperature Sensor reading somewhere between 25°C (77°F) and 125°C (257°F)?
Yes
- Repair is complete.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Replace the EGR Cooler Assembly in accordance with the Service Information. Refer to COOLER, EXHAUST GAS RECIRCULATION (EGR), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .