P040C

P040C-EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR 1 CIRCUIT LOW





For a complete wiring diagram refer to the Wiring Information Electrical Diagrams. Electrical Diagrams

Theory of Operation

The Exhaust Gas Recirculation (EGR) Outlet Temperature Sensor is a variable resistor sensor and is used to measure the temperature of the EGR gas flow after it exits the EGR cooler. The ECM supplies 5-volts to the exhaust gas recirculation temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the EGR outlet temperature. There are two rationality tests. Key-on and engine running. The key-on test fails if the EGR Outlet Temperature Sensor value is different than the key on temperature estimate by more than a calibrated threshold. The engine running test fails if the EGR Outlet Temperature Sensor value does not change by more than a calibrated threshold, over a calibrated period of time. If this fault becomes active the ECM will light the MIL light immediately. During this time the EGR valve will be closed. The ECM turns off the MIL when the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:
When the key is on and battery voltage is above 10.4 volts.

- Set Condition:
The circuit voltage to the ECM is below a calibration threshold for a calibratable period of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure

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 30 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION - DIESEL diagnostic procedure. Intermittent Condition Test

2. (K935) EGR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the ECM C1 harness connector.
3. Disconnect the (K935) EGR Outlet Temperature Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

4. Measure the resistance between ground and the (K935) EGR Outlet Temperature Sensor Signal circuit at the sensor harness connector.

Is the resistance below 10k ohms?

Yes

- Repair the short to ground in the (K935) EGR Outlet Temperature Sensor Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 3

3. (K935) EGR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K914) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (K935) EGR Outlet Temperature Sensor Signal circuit and the (K914) EGR Outlet Temperature Sensor Return circuit at the EGR Outlet Temperature Sensor harness connector.

Is the resistance below 10k ohms?

Yes

- Repair the short between the (K935) EGR Outlet Temperature Sensor Signal circuit and the (K914) EGR Outlet Temperature Sensor Return circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 4

4. EXHAUST GAS RECIRCULATION OUTLET TEMPERATURE SENSOR
1. Measure the resistance between the (K935) EGR Outlet Temperature Sensor Signal circuit and the (K914) EGR Outlet Temperature Sensor Return circuit at the EGR Outlet Temperature Sensor.

Is the resistance between 200.0 ohms and 2.4M ohms?

Yes

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

No

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