DTC Troubleshooting

DTC Troubleshooting: P0406, 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 Initial Inspection and Diagnostic Overview.

1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

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), or press the engine start/stop button to select the OFF mode.

4. Disconnect the EGR valve 5P connector.

5. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

6. Measure the voltage between EGR valve 5P connector terminals No. 3 and No. 4.





Is there about 5 V?

YES -

Go to step 11.

NO -

Go to step 7.

7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

8. Jump the SCS line with the HDS.

9. Disconnect ECM/PCM connector C (49P).

10. Check for continuity between ECM/PCM connector terminal C16 and EGR valve 5P connector terminal No. 3.





Is there continuity?

YES -

Go to step 18.

NO -

Repair open in the wire between the EGR valve and the ECM/PCM (C16), then go to step 13.

11. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

12. Replace the EGR valve Service and Repair.

13. Reconnect all connectors.

14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

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.

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, 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.�