DTC P1780: Problem in Shift Control System
- Clear the DTC with the HDS.
- Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears.
- Check for other DTCs indicated simultaneously with DTC P1780.NOTE: DTC P1780 means there is one or more A/T DTCs about the shift control system.
Are there other DTCs?
YES - Troubleshoot the problem indicated by the DTC. ■
NO - Go to step 4.
- Update the A/T software in the PCM if it does not have the, latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
- Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears.
- Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1780 indicated?
YES - If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step 1
NO - Go to step 1
- Monitor the OBD status for P1780 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 (see PCM REPLACEMENT ). If any other DTCs were indicated on step 6 go to the indicated DTC's troubleshooting. ■
NO - If the HDS indicates FAILED, check for poor connections and loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step 1 If the HDS indicates NOT COMPLETED, return to step 5 and recheck.