DTC Troubleshooting
DTC P0843: Open in 2nd Clutch Transmission Fluid Pressure Switch Circuit, or 2nd Clutch Transmission Fluid Pressure Switch Stuck OFFNOTE:
^ Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.
^ This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
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. Shift into M while pressing the brake pedal, upshift to 2nd gear by pushing the shift lever toward the upshift position (+) or pulling the paddle shifter (upshift switch), and verify with the HDS in the A/T data list that the SHIFT COMMAND indicates 2nd.
4. Check the 2nd PRESSURE SWITCH signal with the HDS in the A/T data list.
Is the 2nd PRESSURE SWITCH ON?
YES - Go to step 5.
NO - Go to step 7.
5. Test-drive the vehicle in 2nd gear in M for at least 2 seconds, then slow down to a stop.
6. Monitor the OBD STATUS for P0843 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate FAILED?
YES - Go to step 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 HDS indicates NOT COMPLETED, return to step 5 and recheck.
7. Turn the ignition switch to LOCK (0).
8. Disconnect the 2nd clutch transmission fluid pressure switch connector.
9. Turn the ignition switch to ON (II).
10. Measure the voltage between the 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 step 17.
NO - Go to step 11.
11. Measure the voltage between PCM connector terminal C11 and body ground.
Is there about 5 V?
YES - Repair open in the wire between PCM connector terminal C11 and the 2nd clutch transmission fluid pressure switch, then go to step 17.
NO - Go to step 12.
12. Connect the 2nd clutch transmission fluid pressure switch connector.
13. Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.
14. Test-drive the vehicle in 2nd gear in M 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.
15. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0843 indicated?
YES - If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.
NO - Go to step 16.
15. Monitor the OBD STATUS for P0843 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated on step 15, go to the indicated DTC's troubleshooting.
NO - Check for poor connections and loose terminals at the 2nd clutch transmission fluid pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 14 and recheck.
17. Clear the DTC with the HDS.
18. Test-drive the vehicle in 2nd gear in M 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.
19. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.
Is DTC P0843 indicated?
YES - Check for poor connections and loose terminals at the 2nd clutch transmission fluid pressure switch and the PCM, then go to step 1.
NO - Go to step 20.
20. Monitor the OBD STATUS for P0843 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the HDS indicate PASSED?
YES - Troubleshooting is complete. If any other DTCs were indicated on step 19, go to the indicated DTC's troubleshooting.
NO - Check for poor connections and loose terminals at the 2nd clutch transmission fluid pressure switch and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 18 and recheck.