DTC Troubleshooting
DTC P0873: Open in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid Pressure Switch Stuck OFFNOTE:
- 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. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
3. Drive the vehicle in 4th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
4. Check the 4th PRESSURE SWITCH SIGNAL with the HDS in the A/T data list.
Is the 4th PRESSURE SWITCH ON?
YES - Go to step 5.
NO - Go to step 7.
5. Drive the vehicle in 4th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
6. Monitor the OBD STATUS for P0873 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES - Go to step 7.
NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the 4th clutch transmission fluid pressure switch and the PCM. If the screen indicates NOT COMPLETED, return to step 5 and recheck.
7. Turn the ignition switch OFF.
8. Disconnect the 4th clutch transmission fluid pressure switch connector.
9. Turn the ignition switch ON (II).
10. Measure voltage between the 4th clutch transmission fluid pressure switch connector terminal and body ground.
Is there about 5 V?
YES - Replace the 4th clutch transmission fluid pressure switch, then go to step 12.
NO - Go to step 11.
11. Measure voltage between PCM connector terminal C20 and body ground.
Is there about 5 V?
YES - Repair an open in the wire between PCM connector terminal C20 and the 4th clutch transmission fluid pressure switch, then go to step 12.
NO - Go to step 19.
12. Reconnect all connectors.
13. Turn the ignition switch ON (II).
14. Clear the DTC with the HDS.
15. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
16. Drive the vehicle in 4th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
17. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0873 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 18.
18. Monitor the OBD STATUS for P0873 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete.
NO - Return to step 6 and recheck.
19. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
20. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
21. Drive the vehicle in 5th gear in the M position for more than 5 seconds. Slow down and stop the wheels.
22. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0873 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 20. If the PCM was substituted, go to step 1.
NO - Go to step 23.
23. Monitor the OBD STATUS for P0873 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete.
NO - Return to step 6 and recheck.