## DTC Troubleshooting: P0405 (12)

DTC P0405: | EGR Valve Position Sensor Cirucuit Low Voltage

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

2. | Do the DTC CLEAR in the CLEAR MENU with the HDS.

3. | Turn the ignition switch OFF.

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

5. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are DTC P0405 and P2127 indicated at the same time? YES - Go to 25. NO - Intermittent failure, system is OK at this time. Go to 6.

6. | Open the throttle to full position several times.

7. | Check the EGR VLS in the DATA LIST with the HDS. Is about 0.1 V or less indicated? YES - Go to 8. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the ECM.n

8. | Turn the ignition switch OFF.

9. | Disconnect the EGR valve 6P connector.

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

11. | Measure voltage between EGR valve 6P connector terminal No. 3 and body ground. Is there about 5 V? YES - Go to 16. NO - Go to 12.

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

13. | Connect the ECM test connector.

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

15. | Measure voltage between test pin box terminal No. 45 and body ground. Is there about 5 V? YES - Repair open in the wire between the ECM connector No. 3 terminal No. 16 (test pin box terminal No. 45) and the EGR valve, then go to 35. NO - go to 40.

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

17. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

18. | Check for continuity between test pin box terinal No. 68 and body ground. Is there continuity? YES - Repair short in the wire between the ECM connector No. 3 terminal No. 39 (test pin box terminal No. 68) and the EGR Valve, then go to 35. NO - Go to 19.

19. | Connect the EGR valve 6P connector terminal No. 1 to body ground with a jumper wire.

20. | Check for continuity between test pin box terminal No. 68 and body ground. Is there continuity? YES - Go to 21. NO - Repair open in the wire between the ECM connector No. 3 terminal No. 39 (test pin box terminal No. 68) and the EGR valve, then go to 35.

21. | Remove the jumper wire from the EGR valve.

22. | Reconnect the EGR valve 6P connector.

23. | Connect the ECM test harness to the ECM.

24. | Measure voltage between test pin box terminal No. 68 and body ground. Is there about 0.1 V or less? YES - Go to 33. NO - Go to 40.

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

26. | Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

27. | Disconnect the connctors from the these sensors: EGR valve APP sensor

28. | Check for continuity between body ground and the test pin box terminals No. 32 and No. 45 individually. Is there continuity? YES - Repair short in the wire between the ECM connector No. 3 terminal No. 3 or No. 16 (test pin box terminal No. 32 or No. 45) and the each sensor, then go to 35. NO - Go to 29.

29. | Connect the ECM test harness to the ECM.

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

31. | Measure voltage between test pin box terminal No. 45 and body ground. Is there about 5 V? YES - Go to 32. NO - Go to 40.

32. | Continue to monitor voltage at the test pin box terminals No. 45 while reconnecting the following sensors, one at a time. EGR valve APP sensor Did the voltage drop to about 0 V? YES - Replace the sensor that caused the voltage to drop, then go to 35. NO - Go to 40.

33. | Turn the ignition switch OFF.

34. | Replace the EGR Valve.

35. | Reconnect all connectors.

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

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

38. | Do the ETCS learn procedure.

39. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0405 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 troublehsooting. NO - Troubleshooting is complete.n

40. | Substitute a known-good ECM.

41. | Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0405 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 troublehsooting. NO - Replace the original ECM.n