DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P0843

DTC P0843 : Transmission Fluid Pressure Switch A (2nd 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. 2nd Pressure Switch signal check:

2nd Pressure Switch signal check
-1. Turn the ignition switch to ON (II).

-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. Shift to 2, and check if the Shift Control indicates 2 with the HDS in the A/T Data List.

-5. Check the 2nd Pressure Switch with the HDS in the A/T Data List.

Is the 2nd Pressure Switch ON?
-YES- The 2nd 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 2nd gear for at least 2 seconds.

-2. Monitor the OBD STATUS for P0843 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 A (2nd clutch) and the PCM. If the HDS indicates NOT COMPLETED, test-drive again.

3. Transmission fluid pressure switch A (2nd clutch) check:

Transmission fluid pressure switch A (2nd 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 A (2nd clutch) , then do the repair verification.
-NO- Go to step 4.

4. Open wire check (OP_2_SW line):

Open wire check (OP_2_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_2_SW wire is OK. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM , then do the repair verification.
-NO- Repair an open in the OP_2_SW wire between transmission fluid pressure switch A (2nd 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 2nd and 4th gears for at least 2 seconds in each gear.

-6. Monitor the OBD STATUS for P0843 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 . 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 , and check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.