## DTC Troubleshooting: P0406 (12)

DTC P0406 | EGR Valve Position Sensor Circuit High Voltage

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

2. | Check the EGR VLS in the DATA LIST with the HDS. Is about 4.9 V or higher indicated? YES - Go to 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the ECM.n

3. | Turn the ignition switch OFF, and wait 10 seconds.

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 11. NO - Go to 7.

7. | Turn the ignition switch OFF, and wait 10 seconds.

8. | Connect the ECM test harness and the test pin box between the ECM and connector.

9. | Turn the ignition switch ON (II).

10. | Measure voltage between test pin box teriminals No. 45 and No. 62. Is there about 5 V? YES - Repair open in the wire between the ECM connector No. 3 terminal No. 33 (test pin box terminal No. 62) and the EGR valve, then go to 13. NO - Go to 18.

11. | Turn the ignition switch OFF.

12. | Replace the EGR valve.

13. | Reconnect all connectors.

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

15. | Do the ECM RESET in the CLEAR MENU with the HDS.

16. | Do the ETCS learn procedure.

17. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0406 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting. NO - Troubleshooting is complete.n

18. | Substitute a known-good ECM.

19. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0406 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM, then go to 1. if any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting. NO - Replace the original ECM.