P1077
DTC P1077: IMT Valve Stuck in High RPM PositionNOTE: 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. Clear the DTC with the HDS.
3. Do the IMT TEST in the INSPECTION MENU with the HDS.
Is the result OK?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the IMT actuator and the ECM/PCM.
NO - Go to step 4.
4. Turn the ignition switch OFF.
5. Disconnect the IMT actuator 5P connector.
6. Turn the ignition switch ON (II).
7. Measure voltage between IMT actuator 5P connector terminal No. 1 and body ground.
Is there about 5V?
YES - Go to step 12.
NO - Go to step 8.
8. Turn the ignition switch OFF.
9. Jump the SCS line with the HDS.
10. Disconnect ECM/PCM connector B (44P).
11. Check for continuity between IMT actuator 5P connector terminal No. 1 and ECM/PCM connector terminal B18.
Is there continuity?
YES - Go to step 36.
NO - Repair open in the wire between the ECM/PCM (B18) and the IMT actuator, then go to step 30.
12. Measure voltage between IMT actuator 5P connector terminal No. 3 and body ground.
Is there about 5 V?
YES - Go to step 17.
NO - Go to step 13.
13. Turn the ignition switch OFF.
14. Jump the SCS line with the HDS.
15. Disconnect ECM/PCM connector B (44P).
16. Check for continuity between IMT actuator 5P connector terminal No. 3 and ECM/PCM connector terminal B39.
Is there continuity?
YES - Go to step 36.
NO - Repair open in the wire between the ECM/PCM (B39) and the IMT actuator, then go to step 30.
17. Turn the ignition switch OFF.
18. Jump the SCS line with the HDS.
19. Disconnect ECM/PCM connector B (44P).
20. Check for continuity between IMT actuator 5P connector terminal No. 2 and ECM/PCM connector terminal B33.
Is there continuity?
YES - Go to step 21.
NO - Repair open in the wire between the ECM/PCM (B33) and the IMT actuator, then go to step 30.
21. Check for continuity between ECM/PCM connector terminal B37 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (B37) and the IMT actuator, then go to step 30.
NO - Go to step 22.
22. Check for continuity between ECM/PCM connector terminal B38 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (B38) and the IMT actuator, then go to step 30.
NO - Go to step 23.
23. Check for continuity between IMT actuator 5P connector terminal No. 4 and ECM/PCM connector terminal B37.
24. Check for continuity between IMT actuator 5P connector terminal No. 5 and ECM/PCM connector terminal B38.
Is there continuity?
YES - Go to step 25.
NO - Repair open in the wire between the ECM/PCM (B38) and the IMT actuator, then go to step 30.
25. Remove the IMT actuator.
26. Move the IMT valve by hand.
Does it move smoothly?
YES - Go to step 27.
NO - Replace the IMT valve, then go to step 30.
27. Substitute a known-good IMT actuator.
28. Turn the ignition switch ON (II).
29. Do the IMT TEST in the INSPECTION MENU with the HDS.
Is the result OK?
YES - Replace the original IMT actuator, then go to step 30.
NO - Go to step 36.
30. Reconnect all connectors.
31. Turn the ignition switch ON (II).
32. Reset the ECM/PCM with the HDS.
33. Do the ECM/PCM idle learn procedure.
34. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1077 indicated?
YES - Check for poor connections or loose terminals at the IMT actuator and the ECM/PCM, then go to step 1.
NO - Go to step 35.
35. Monitor the OBD STATUS for DTC P1077 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 34, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the IMT actuator and the ECM/PCM, then go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.
36. Reconnect all connectors.
37. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
38. Start the engine, and let it idle.
39. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1077 indicated?
YES - Check for poor connections or loose terminals at the IMT actuator and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 38. If the ECM/PCM was substituted, go to step 1.
NO - Go to step 40.
40. Monitor the OBD STATUS for DTC PT077 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - 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 were indicated in step 39, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the IMT actuator and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 38. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.