DTC Troubleshooting

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.

1. Turn the ignition switch ON (II).
2. Check the EGR VLS in the DATA LIST with the HDS.

Is 4.88 V or higher 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 OFF.
4. Disconnect the EGR valve 6P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between EGR valve 6P connector terminals No. 2 and No. 3.






Is there about 5 V?

YES - Go to step 8.

NO - Go to step 7.

7. Measure voltage between ECM/PCM connector terminals C14 and C12.






Is there about 5 V?

YES - Repair open in the wire between the EGR valve and the ECM/PCM (C12), then go to step 10.

NO - Go to step 14.

8. Turn the ignition switch OFF.
9. Replace the EGR valve.
10. Turn the ignition switch ON (II).
11. Reset the ECM/PCM with the HDS.
12. Do the ECM/PCM idle learn procedure.
13. Check for Temporary DTCs or 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 Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

14. Turn the ignition switch OFF.
15. Reconnect all connectors.
16. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
17. Check for Temporary DTCs or 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, 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. If any other Temporary DTCs or DTCs are indicated DTCs troubleshooting.