Automatic Transmission
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 D for at least 2 seconds, then drive in 5th gear for at least 2 seconds.
4. Check the 4TH PRESSURE SWITCH SIGNAL in the DATA LIST with the HDS.
Is the 4TH PRESSURE SWITCH ON?
YES - Go to step 5.
NO - Go to step 7.
5. Drive the vehicle in 4th gear in D for at least 2 seconds, then drive in 5th gear for at least 2 seconds.
6. Monitor the OBD STATUS for P0873 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - 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.
NO - If the screen indicates NOT COMPLETED, return to step 5 and recheck.
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. Measure the voltage between the 4th clutch transmission fluid pressure switch connector terminal and body ground.
Is there about 5 V?
YES - 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 (44P).
14. Check for continuity between PCM connector terminal C16 and 4th clutch transmission fluid pressure switch connector terminal.
Is there continuity?
YES - Go to step 23.
NO - Repair an open in the wire between PCM connector terminal C16 and the 4th clutch transmission fluid pressure switch, then go to step 16.
15. Replace the 4th clutch transmission fluid pressure switch.
16. Reconnect all connectors.
17. Turn the ignition switch to ON (II).
18. Clear the DTC with HDS.
19. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
20. Drive the vehicle in 4th gear in D for at least 2 seconds, then drive in 5th gear for at least 2 seconds.
21. 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 - If Temporary DTC or DTC P0873 is not indicated, or if any other Temporary DTCs are indicated, go to step 22.
22. Monitor the OBD STATUS for P0873 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTC or DTCs were indicated on step 21, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the 4th clutch transmission fluid pressure switch and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 19.
23. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
24. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
25. Drive the vehicle in 4th gear in D for at least 2 seconds, then drive in 5th gear for at least 2 seconds.
26. 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 24. If the PCM was substituted, go to step 1.
NO - If Temporary DTC or DTC P0873 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 27.
27. Monitor the OBD STATUS for P0873 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 Temporary DTCs or DTCs were indicated on step 26, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, 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 24. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 24.