DTC Troubleshooting
DTC Troubleshooting: P0848 (26)
DTC P0848:
Open in Transmission Fluid Pressure Switch B (3rd Clutch) Circuit, or Transmission Fluid Pressure Switch B (3rd Clutch) Stuck OFF
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information Reading and Clearing Diagnostic Trouble Codes.
1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
2. Clear the DTC with the HDS.
3. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
4. Test-drive the vehicle in 3rd gear in D, and verify with the HDS in the A/T Data List that the Shift Control indicates 3rd.
5. 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 6.
NO -
Go to step 8.
6. Test-drive the vehicle in 3rd gear in D for at least 2 seconds. Slow down, and stop the wheels.
7. Monitor the OBD status for P0848 in the DTCs MENU with the HDS.
Does the HDS indicate FAILED?
YES -
Go to step 8.
NO -
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at transmission fluid pressure switch B (3rd clutch) and the PCM. If the HDS indicates NOT COMPLETED, go to step 6.
8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
9. Disconnect the transmission fluid pressure switch B (3rd clutch) connector.
10. Connect a jumper wire between the transmission fluid pressure switch B (3rd clutch) connector terminal and body ground.
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
12. 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 13.
NO -
Go to step 16.
13. Reconnect the transmission fluid pressure switch B (3rd clutch) connector.
14. Clear the DTC with the HDS.
15. Measure the 3rd clutch pressure A/T Pressure Test.
Is the 3rd clutch pressure within the service limit?
YES -
Replace transmission fluid pressure switch B (3rd clutch) Transmission Fluid Pressure Switch B (3rd Clutch) Replacement, then go to step 20.
NO -
Replace shift valves A, B, and C, and the related hydraulic circuit, or replace the transmission, then go to step 23.
16. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
17. Jump the SCS line with the HDS.
18. Disconnect PCM connector C (49P).
19. Check for continuity between PCM connector terminal C38 and the transmission fluid pressure switch B (3rd clutch) connector terminal.
Is there continuity?
YES -
Go to step 27.
NO -
Repair an open in the wire between PCM connector terminal C38 and transmission fluid pressure switch B (3rd clutch), then go to step 20.
20. Reconnect all connectors.
21. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
22. Clear the DTC with the HDS.
23. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
24. Test-drive the vehicle in 3rd gear in D for at least 2 seconds, then press the accelerator pedal so that the transmission upshifts to 4th gear. Drive the vehicle 4th gear for at least 2 seconds. Slow down, and stop the wheels.
25. 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 26.
26. 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 25, 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 23.
27. Reconnect all connectors.
28. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM.
29. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
30. Test-drive the vehicle in 3rd gear in D for at least 2 seconds, then press the accelerator pedal so that the transmission upshifts to 4th gear. Drive the vehicle 4th gear for at least 2 seconds. Slow down, and stop the wheels.
31. 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. If the PCM was updated, substitute a known-good PCM, then go to step 29. If the PCM was substituted, go to step 1.
NO -
Go to step 32.
32. 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 31, 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, then go to step 29. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 29.