Transmission Control Systems

DTC P1780: Problem in Shift Control System

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.

1. Clear the DTC with the HDS.
2. Test-drive the vehicle for several minutes in the D position through all five gears, then slow down to a stop.
3. Retest-drive the vehicle for several minutes in the D position through all five gears, then slow down to a stop.
4. Check for other DTCs indicated simultaneously with DTC P1780.

NOTE: DTC P1780 means there is one or more A/T DTCs regarding the shift control system.

Are there other DTCs?
YES - Troubleshoot the problems as indicated by the DTCs.
NO - Go to step 5.

5. Update the PCM if it does not have latest software, or substitute a known-good PCM.
6. Test-drive the vehicle for several minutes in the D position through all five gears, then slow down to a stop.
7. Retest-drive the vehicle for several minutes in the D position through all five gears, then slow down to a stop.
8. Monitor the OBD status for P1780 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.
NO - If the PCM was updated and screen indicates FAILED, substitute a known-good PCM, then go to step 1. If the PCM was substituted, go to step 1.