DTC Troubleshooting
DTC Troubleshooting: P0872 (27)
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 with the HDS, and review General Troubleshooting Information How To Troubleshoot The A/T System.
- 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 to ON (II).
2. Clear the DTC with the HDS.
3. Check the 4th Pressure Switch with the HDS in the A/T Data List in any position other than 4th.
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. Test-drive the vehicle in 5th gear with the shift lever in D for at least 2 seconds.
6. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.
Does the HDS indicate FAILED?
YES -
Go to step 7.
NO -
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check the OP4SW wire for an intermittent short to body ground in the wire between the 4th clutch transmission fluid pressure switch and the PCM. If the HDS indicates NOT COMPLETED, go to step 4.
7. Turn the ignition switch to LOCK (0).
8. Disconnect the 4th clutch transmission fluid pressure switch connector.
9. Turn the ignition switch to ON (II).
10. Check the 4th Pressure Switch with the HDS in the A/T Data List.
Is the 4th Pressure Switch OFF?
YES -
Replace the 4th clutch transmission fluid pressure switch 4th Clutch Transmission Fluid Pressure Switch Replacement, then go to step 15.
NO -
Go to step 11.
11. Turn the ignition switch to LOCK (0).
12. Jump the SCS line with the HDS.
13. Disconnect PCM connector C (49P).
14. Check for continuity between PCM connector terminal C37 and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between PCM connector terminal C37 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 to 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. Test-drive the vehicle in 4th gear with the shift lever in D for at least 2 seconds. Then drive in 5th gear for at least 2 seconds.
20. Check for Pending or Confirmed 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 HDS indicate PASSED?
YES -
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 20, go to the indicated DTC's troubleshooting.�
NO -
If the HDS indicates FAILED, 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. If the HDS indicates NOT COMPLETED, go to step 18.
22. Reconnect all connectors.
23. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM Initial Inspection and Diagnostic Overview.
24. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
25. Test-drive the vehicle in 4th gear with the shift lever in D for at least 2 seconds. Then drive in 5th gear for at least 2 seconds.
26. Check for Pending or Confirmed 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 Initial Inspection and Diagnostic Overview, then go to step 24. If the PCM was substituted, go to step 1.
NO -
Go to step 27.
27. Monitor the OBD STATUS for P0872 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?
YES -
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 26, go to the indicated DTC's troubleshooting.�
NO -
If the HDS 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 Initial Inspection and Diagnostic Overview, then go to step 24. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 24.