DTC Troubleshooting
DTC Troubleshooting: P0847 (26)
DTC P0847:
Transmission Fluid Pressure Switch B (3rd Clutch) Circuit Low
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. Clear the DTC with the HDS.
2. Check the 3rd Pressure Switch signal with the HDS in the A/T Data List when not in 3rd gear.
Is the 3rd Pressure Switch OFF?
YES -
Go to step 3.
NO -
Go to step 6.
3. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
4. Test-drive the vehicle in 4th gear with the shift lever in S for at least 2 seconds. Slow down, and stop the wheels.
5. Monitor the OBD STATUS for P0847 in the DTCs MENU with the HDS.
Does the HDS indicate FAILED?
YES -
Go to step 6.
NO -
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check the OP3SW wire for intermittent short to body ground between transmission fluid pressure switch B (3rd clutch) and the PCM. If the HDS indicates NOT COMPLETED, go to step 4.
6. Turn the ignition switch to LOCK (0).
7. Disconnect transmission fluid pressure switch B (3rd clutch) connector.
8. Turn the ignition switch to ON (II).
9. Check the 3rd Pressure Switch signal with the HDS in the A/T Data List.
Is the 3rd Pressure Switch OFF?
YES -
Replace transmission fluid pressure switch B (3rd clutch) Transmission Fluid Pressure Switch B (3rd Clutch) Replacement, then go to step 20.
NO -
Go to step 10.
10. Turn the ignition switch to LOCK (0).
11. Jump the SCS line with the HDS.
12. Disconnect PCM connector B (44P).
13. Check for continuity between PCM connector terminal B9 and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between PCM connector terminal B9 and transmission fluid pressure switch B (3rd clutch), then go to step 20.
NO -
Go to step 14.
14. Reconnect all connectors.
15. Update the A/T software in the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM Initial Inspection and Diagnostic Overview.
16. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
17. Test-drive the vehicle in 3rd gear with the shift lever in S for at least 2 seconds, then upshift to 4th gear, and drive in 4th gear for at least 2 seconds. Slow down, and stop the wheels.
18. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0847 indicated?
YES -
If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 16. If the PCM was substituted, go to step 1.
NO -
Go to step 19.
19. Monitor the OBD STATUS for P0847 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 18, go to the indicated DTC's troubleshooting.�
NO -
If the HDS indicates FAILED, check for intermittent short to body ground in the wire between transmission fluid pressure switch B (3rd clutch) and the PCM. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 16. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 17.
20. Reconnect all connectors.
21. Clear the DTC with the HDS.
22. Start the engine in P, and warm it up to normal operating temperature (the radiator fan comes on).
23. Test-drive the vehicle in 3rd gear with the shift lever in S for at least 2 seconds, then upshift to 4th gear, and drive in 4th gear for at least 2 seconds. Slow down, and stop the wheels.
24. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0847 indicated?
YES -
Check for intermittent short to body ground in the wire between transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1.
NO -
Go to step 25.
25. Monitor the OBD STATUS for P0847 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 24, go to the indicated DTC's troubleshooting.�
NO -
If the HDS indicates FAILED, check for intermittent short to body ground in the wire between transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 23.