DTC Troubleshooting
DTC Troubleshooting: P0848 (26)
DTC P0848:
Transmission Fluid Pressure Switch B (3rd Clutch) Circuit High
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.
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 3rd gear with the shift lever in S, and verify with the HDS in the A/T Data List that the Shift Command indicates 3rd.
4. Check the 3rd Pressure Switch signal with the HDS in the A/T Data List.
Is the 3rd Pressure Switch ON?
YES -
Go to step 5.
NO -
Go to step 7.
5. Test-drive the vehicle in 3rd gear with the shift lever in S for at least 2 seconds. Slow down, and stop the wheels.
6. Monitor the OBD STATUS for P0848 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 transmission fluid pressure switch B (3rd clutch) and the PCM. If the HDS indicates NOT COMPLETED, go to step 5.
7. Turn the ignition switch to LOCK (0).
8. Disconnect transmission fluid pressure switch B (3rd clutch) connector.
9. Connect a jumper wire between the transmission fluid pressure switch B (3rd clutch) connector terminal and body ground.
10. Turn the ignition switch to ON (II).
11. Check the 3rd Pressure Switch signal with the HDS in the A/T Data List.
Is the 3rd Pressure Switch ON?
YES -
Go to step 12.
NO -
Go to step 15.
12. Reconnect transmission fluid pressure switch B (3rd clutch) connector.
13. Clear the DTC with the HDS.
14. Measure the 3rd clutch pressure A/T Pressure Test.
Is the 3rd clutch pressure within the service limits?
YES -
Replace transmission fluid pressure switch B (3rd clutch) Transmission Fluid Pressure Switch B (3rd Clutch) Replacement, then go to step 25.
NO -
Repair shift valves A and B, 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 B (44P).
18. Check for continuity between PCM connector terminal B9 and transmission fluid pressure switch B (3rd clutch) connector terminal.
Is there continuity?
YES -
Go to step 19.
NO -
Repair open in the wire between PCM connector terminal B9 and transmission fluid pressure switch B (3rd clutch), 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 Initial Inspection and Diagnostic Overview.
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 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.
23. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0848 indicated?
YES -
If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, 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 P0848 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 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 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 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.
29. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0848 indicated?
YES -
Check for poor connections or loose terminals between transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1.
NO -
Go to step 30.
30. Monitor the OBD STATUS for P0848 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 transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 28.