DTC Troubleshooting

DTC P0872: Short in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck ON

NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.
- This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. Clear the DTC with the HDS.
2. Check the 4th PRESSURE SWITCH SIGNAL with the HDS in the A/T data list when not in 4th gear.

Is the 4th PRESSURE SWITCH OFF?

YES - Go to step 3.

NO - Go to step 6.

3. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
4. Drive the vehicle in 5th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
5. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 6.

NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. Check the OP4SW (BLU/YEL) wire for an intermittent short to body ground between the 4th clutch transmission fluid pressure switch and the PCM. If the screen indicates NOT COMPLETED, return to step 3 and recheck.

6. Turn the ignition switch OFF.
7. Disconnect the 4th clutch transmission fluid pressure switch connector.
8. Turn the ignition switch ON (II).
9. Check the 4th PRESSURE SWITCH SIGNAL with the HDS in the A/T data list.

Is the 4th PRESSURE SWITCH OFF?

YES - Replace the 4th clutch transmission fluid pressure switch, then go to step 14.

NO - Go to step 10.

10. Turn the ignition switch OFF.
11. Jump the SCS line with the HDS.
12. Disconnect PCM connector C (22P).
13. Check for continuity between PCM connector terminal C20 and body ground.





Is there continuity?

YES - Repair a short to body ground in the wire between PCM connector terminal C20 and the 4th clutch transmission fluid pressure switch, then go to step 14.

NO - Go to step 21.

14. Reconnect all connectors.
15. Turn the ignition switch ON (II).
16. Clear the DTC with the HDS.
17. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
18. Drive the vehicle in 5th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
19. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0872 indicated?

YES - Check for poor connections or loose terminals at the 4th clutch transmission fluid pressure switch and the PCM, then go to step 1.

NO - Go to step 20.

20. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

NO - Return to step 6 and recheck.

21. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
22. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
23. Drive the vehicle in 5th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
24. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0872 indicated?

YES - Check for poor connections or loose terminals at the 4th clutch transmission fluid pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 22. If the PCM was substituted, go to step 1.

NO - Go to step 25.

25. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

NO - Return to step 6 and recheck.