DTC Troubleshooting
DTC Troubleshooting: P0873 (27)
DTC P0873:
4th Clutch Transmission Fluid Pressure Switch Circuit High
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information How to Troubleshoot the A/T System.
1. Clear the DTC with the HDS.
2. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
3. Test-drive the vehicle in 4th gear with the shift lever in S, and verify with the HDS in the A/T Data List that the Shift Command indicates 4th.
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. Test-drive the vehicle in 4th gear with the shift lever in S for at least 2 seconds. Slow down, and stop the wheels.
6. Monitor the OBD STATUS for P0873 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 for poor connections or loose terminals between the 4th clutch transmission fluid pressure switch and the PCM. If the HDS indicates NOT COMPLETED, go to step 5.
7. Turn the ignition switch to LOCK (0).
8. Disconnect the 4th clutch transmission fluid pressure switch connector.
9. Connect a jumper wire between the 4th clutch transmission fluid pressure switch connector terminal and body ground.
10. Turn the ignition switch to ON (II).
11. 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 12.
NO -
Go to step 15.
12. Reconnect the 4th clutch transmission fluid pressure switch connector.
13. Clear the DTC with the HDS.
14. Measure the 4th clutch pressure A/T Pressure Test.
Is the 4th clutch pressure within the service limits?
YES -
Replace the 4th clutch transmission fluid pressure switch 4th Clutch Transmission Fluid Pressure Switch Replacement, then go to step 25.
NO -
Repair shift valves B, C, and E, and related hydraulic circuit, or replace the transmission, then go to step 27.
15. Turn the ignition switch to LOCK (0).
16. Jump the SCS line with the HDS.
17. Disconnect PCM connector C (44P).
18. Check for continuity between PCM connector terminal C38 and the 4th clutch transmission fluid pressure switch connector terminal.
Is there continuity?
YES -
Go to step 19.
NO -
Repair an open in the wire between PCM connector terminal C38 and the 4th clutch transmission fluid pressure switch, then go to step 25.
19. Reconnect all connectors.
20. Update the A/T software in the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
21. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
22. Test-drive the vehicle in 4th gear with the shift lever in S for at least 2 seconds, then upshift to 5th gear by pressing the paddle shifter + (upshift switch), and drive in 5th gear for at least 2 seconds. Slow down, and stop the wheels.
23. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0873 indicated?
YES -
If the PCM was updated, substitute a known-good PCM, then go to step 21. If the PCM was substituted, go to step 1.
NO -
Go to step 24.
24. Monitor the OBD STATUS for P0873 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 23, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals 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 21. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 22.
25. Reconnect all connectors.
26. Clear the DTC with the HDS.
27. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
28. Test-drive the vehicle in 4th gear with the shift lever in S for at least 2 seconds, then upshift to 5th gear by pressing the paddle shifter + (upshift switch), and drive in 5th gear for at least 2 seconds. Slow down, and stop the wheels.
29. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0873 indicated?
YES -
Check for poor connections or loose terminals between the 4th clutch transmission fluid pressure switch and the PCM, then go to step 1.
NO -
Go to step 30.
30. Monitor the OBD STATUS for P0873 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 29, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals 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 28.