DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0848

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 the General Troubleshooting Information How To Troubleshoot The A/T System.

1. 3rd Pressure Switch signal check:

3rd Pressure Switch signal check
-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS.

-3. Block the rear wheels and raise the front of the vehicle, or raise the vehicle on a lift. Make sure it is securely supported, and allow the front wheels to rotate freely.

-4. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).

-5. Start the engine, disable the VSA by pressing the VSA OFF button. Run the vehicle in 3rd gear, and check the 3rd Pressure Switch with the HDS in the A/T Data List.

Is the 3rd Pressure Switch ON in 3rd gear?
-YES- The 3rd Pressure Switch signal is OK. Go to step 2.
-NO- Go to step 3.

2. Problem verification:

Problem verification
-1. Test-drive the vehicle in 3rd gear for at least 2 seconds.

-2. Monitor the OBD STATUS for P0848 in the DTCs MENU with the HDS.

Does the HDS indicate FAILED?
-YES- The failure is duplicated. Go to step 3.
-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, test-drive again.

3. Transmission fluid pressure switch B (3rd clutch) check:

Transmission fluid pressure switch B (3rd clutch) check
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there about 5 V?
-YES- Replace transmission fluid pressure switch B (3rd clutch) Transmission Fluid Pressure Switch B (3rd Clutch) Removal and Installation, then do the repair verification.
-NO- Go to step 4.

4. Open wire check (OP_3_SW line):

Open wire check (OP_3_SW line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The OP_3_SW wire is OK. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM Service and Repair, then do the repair verification.
-NO- Repair an open in the OP_3_SW wire between transmission fluid pressure switch B (3rd clutch) and the PCM, then do the repair verification.

Repair verification (OBD STATUS check):

-1. Reconnect all connectors.

-2. Turn the ignition switch to ON (II).

-3. Clear the DTC with the HDS.

-4. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).

-5. Test-drive the vehicle in 3rd gear for at least 2 seconds, then drive in 4th gear for at least 2 seconds.

-6. Monitor the OBD STATUS for P0848 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
-PASSED- Troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM Service and Repair, and check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.