DTC Troubleshooting
DTC Troubleshooting: P0843 (25)
DTC P0843:
Open in Transmission Fluid Pressure Switch A (2nd Clutch) Circuit, or Transmission Fluid Pressure Switch A (2nd 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).
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 while pressing the brake pedal, and check that the Shift Control indicates 2 in the Data List with the HDS.
5. Check the 2nd Pressure Switch in the Data List with the HDS.
Is the 2nd Pressure Switch ON?
YES -
Go to step 6.
NO -
Go to step 8.
6. Test-drive the vehicle in 2nd gear with the shift lever in D for at least 2 seconds.
7. Monitor the OBD STATUS for P0843 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 between transmission fluid pressure switch A (2nd clutch) and the PCM. If the HDS indicates NOT COMPLETED, go to step 5.
8. Turn the ignition switch to LOCK (0).
9. Disconnect the transmission fluid pressure switch A (2nd clutch) connector.
10. Turn the ignition switch to ON (II).
11. Measure the voltage between the transmission fluid pressure switch A (2nd clutch) connector terminal and body ground.
Is there about 5 V?
YES -
Replace transmission fluid pressure switch A (2nd clutch) Transmission Fluid Pressure Switch A (2ND Clutch) Replacement, then go to step 13.
NO -
Go to step 12.
12. Measure the voltage between PCM connector terminal C13 and body ground.
Is there about 5 V?
YES -
Repair an open in the wire between PCM connector terminal C13 and transmission fluid pressure switch A (2nd clutch), then go to step 13.
NO -
Go to step 20.
13. Reconnect all connectors.
14. Turn the ignition switch to ON (II).
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. Test-drive the vehicle in 2nd gear with the shift lever in D for at least 2 seconds. Then drive in 4th gear for at least 2 seconds.
18. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0843 indicated?
YES -
Check for poor connections or loose terminals between transmission fluid pressure switch A (2nd clutch) and the PCM, then go to step 1.
NO -
Go to step 19.
19. Monitor the OBD STATUS for P0843 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 18, 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 A (2nd clutch) and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 16.
20. Reconnect all connectors.
21. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM.
22. Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
23. Test-drive the vehicle in 2nd gear with the shift lever in D for at least 2 seconds. Then drive in 4th gear for at least 2 seconds.
24. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0843 indicated?
YES -
Check for poor connections or loose terminals between transmission fluid pressure switch A (2nd clutch) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 22. If the PCM was substituted, go to step 1.
NO -
Go to step 25.
25. Monitor the OBD STATUS for P0843 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 ECM/PCM Replacement (A/T). If any other Pending or Confirmed DTCs were indicated in step 24, 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 A (2nd clutch) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 22. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 22.