P0406

DTC Troubleshooting: P0406

DTC P0406: EGR Valve Position Sensor Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Reading and Clearing Diagnostic Trouble Codes

1. Turn the ignition switch to ON (II).

2. Check the EGR VLS in the DATA LIST with the HDS.

Is 4.88 V or more indicated?
YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the ECM/PCM.


3. Turn the ignition switch to LOCK (0).

4. Disconnect the EGR valve 6P connector.

5. Turn the ignition switch to ON (II).

6. Measure the voltage between EGR valve 6P connector terminals No. 2 and No. 3.

Is there about 5 V?
YES - Go to step 11.

NO - Go to step 7.






7. Turn the ignition switch to LOCK (0).

8. Jump the SCS line with the HDS.

9. Disconnect ECM/PCM connector B (44P).

10. Check for continuity between EGR valve 6P connector terminal No. 2 and ECM/PCM connector terminal B33.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wire between the ECM/PCM (B33) and the EGR valve, then go to step 13.






11. Turn the ignition switch to LOCK (0).

12. Replace the EGR valve. Service and Repair

13. Reconnect all connectors.

14. Turn the ignition switch to ON (II).

15. Reset the ECM/PCM with the HDS.

16. Do the ECM/PCM idle learn procedure. ECM/PCM Idle Learn Procedure

17. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0406 indicated?
YES - Check for poor connections or loose terminals at the EGR valve and the ECM/PCM, then go to step 1.

NO - Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.


18. Reconnect all connectors.

19. Update the ECM/PCM if it does not have the latest software, ECM/PCM Update or substitute a known-good ECM/PCM. Reading and Clearing Diagnostic Trouble Codes

20. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0406 indicated?
YES - Check for poor connections or loose terminals at the EGR valve and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the ECM/PCM was substituted, go to step 1.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. Service and Repair If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.