DTC Troubleshooting: P0843 (25-4)

DTC P0843:  Open in 2nd Clutch Transmission Fluid Pressure Switch Circuit, or 2nd Clutch Transmission Fluid Pressure Switch Stuck OFF

NOTE:

1.Clear the DTC with the HDS.

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

3.7-position transmission: Shift to the 2 position.
5-position transmission: Shift to the S position, then select 2nd gear by pressing the steering wheel upshift (+) switch.

4.Check the 2nd PRES SWITCH signal with the HDS in the A/T data list.

Is the 2nd PRES SWITCH ON?


YES - Go to 5.


NO - Go to 7.


5.7-position transmission: Drive the vehicle in the 2 position for more than 5 seconds, then shift to the D position, and drive in 3rd gear for more than 5 seconds. Slow down and stop the wheels.
5-position transmission: Drive the vehicle in 2nd gear in the S position for more than 5 seconds, then upshift to 3rd gear, and drive in 3rd gear for more than 5 seconds. Slow down and stop the wheels.

6.Monitor the OBD status for P0843 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the result indicate FAILED?


YES - Go to 7.


NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the 2nd clutch transmission fluid pressure switch and the PCM. If the tester indicates NOT COMPLETED, return to 5 and recheck.n

7.Turn the ignition switch OFF.

8.Disconnect the 2nd clutch transmission fluid pressure switch connector.

9.Turn the ignition switch ON (II).

10.Measure voltage between 2nd clutch transmission fluid pressure switch connector terminal and body ground.

 

Is there about 5 V?


YES - Replace the 2nd clutch transmission fluid pressure switch, then go to 15.


NO - Go to 11.

11.Turn the ignition switch OFF.

12.Jump the SCS line with the HDS.

13.Disconnect PCM connector B (44P).

14.Check for continuity between PCM connector terminal B8 and 2nd clutch transmission fluid pressure switch connector terminal.

 

Is there continuity?


YES - Check for loose or poor connections at PCM connector terminal B8. If the connection is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original  PCM.n


NO - Repair open in the wire between PCM connector terminal B8 and the 2nd clutch transmission fluid pressure switch, then go to 15.

15.Clear the DTC with the HDS.

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

17.7-position transmission: Drive the vehicle in the 2 position for more than 5 seconds, then shift to the D position, and drive in 3rd gear for more than 5 seconds. Slow down and stop the wheels.
5-position transmission: Drive the vehicle in 2nd gear in the S position for more than 5 seconds, then upshift to 3rd gear for more than 5 seconds. Slow down and stop the wheels.

18.Monitor the OBD status for P0843 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the result indicate PASSED?


YES - Troubleshooting is complete.n


NO - Return to 7 and recheck.