P040B

P040B-EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR "A" CIRCUIT PERFORMANCE





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

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 Powertrain Control Module (PCM) supplies 5-Volts to the exhaust gas recirculation temperature signal circuit. The PCM 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 compares the EGR Outlet Temperature Sensor value with the Engine Coolant Temperature Sensor and Inlet Air Temperature Sensor. The key-on test fails if the EGR Outlet Temperature Sensor value is different than the key on Engine Coolant Temperature Sensor and Inlet Air Temperature Sensor 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 PCM will light the MIL light immediately. During this time the EGR valve will be closed. The PCM turns off the MIL when the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
EGR Outlet Temperature and exhaust temperature below a calibrated range at key on.

- Set Condition:
The key-on test fails if the EGR Outlet Temperature Sensor value is different than the key on Engine Coolant Temperature Sensor and Inlet Air Temperature Sensor 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.





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

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.

Is the DTC active?

Yes

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

No

- Go To 2

2. CHECK THE EXHAUST GAS RECIRCULATION TEMPERATURE SENSOR
1. Turn the ignition off.
2. Disconnect the EGR Outlet Temperature Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Remove the EGR Outlet Temperature Sensor and reconnect the wiring harness connector to the sensor.
4. Turn the Ignition on, engine off.
5. Monitor scan tool, while heating the sensor with an external heat source (DO NOT USE OPEN FLAME).

Does the reading from the sensor increase at least 2.78°C (5°F) on the scan tool?

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

No

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