DTC Troubleshooting
DTC P0872: Short in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck ONNOTE:
^ 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. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check the 4th PRESSURE SWITCH in the DATA LIST with the HDS when not in 4th gear.
Is the 4th PRESSURE SWITCH OFF?
YES - Go to step 4.
NO - Go to step 7.
4. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
5. Drive the vehicle in 4th gear in the M position for more than 5 seconds.
6. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 7.
NO - Intermittent failure, the system is OK at this time. Check for intermittent short to body ground in the wire between the 4th clutch transmission fluid pressure switch and the PCM. If the screen indicates NOT COMPLETED, go to step 4.
7. Turn the ignition switch OFF.
8. Disconnect the 4th clutch transmission fluid pressure switch connector.
9. Turn the ignition switch ON (II).
10. Check the 4th PRESSURE SWITCH in the DATA LIST with the HDS.
Is the 4th PRESSURE SWITCH OFF?
YES - Replace the 4th clutch transmission fluid pressure switch, then go to step 15.
NO - Go to step 11.
11. Turn the ignition switch OFF.
12. Jump the SCS line with the HDS.
13. Disconnect PCM connector C (22P).
14. Check for continuity between PCM connector terminal C20 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between PCM connector terminal C20 and the 4th clutch transmission fluid pressure switch, then go to step 15.
NO - Go to step 22.
15. Reconnect all connectors.
16. Turn the ignition switch ON (II).
17. Clear the DTC with the HDS.
18. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
19. Drive the vehicle in 4th gear in the M position, for more than 5 seconds.
20. Check for DTCs with the HDS.
Is DTC P0872 indicated?
YES - Check for intermittent short to body ground in the wire between the 4th clutch transmission fluid pressure switch and the PCM, then go to step 1.
NO - Go to step 21.
21. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated in step 20, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals in the wire between the 4th clutch transmission fluid pressure switch and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 18.
22. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
23. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
24. Drive the vehicle in 4th gear in the M position, for more than 5 seconds.
25. Check for DTCs with the HDS.
Is DTC P0872 indicated?
YES - Check for intermittent short to body ground in the wire between the 4th clutch transmission fluid pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 23. If the PCM was substituted, go to step 1.
NO - Go to step 26.
26. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated in step 25, go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for intermittent short to body ground in the wire between the 4th clutch transmission fluid pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 23. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 23.