DTC P1780: Problem in Shift Control System4.
- Clear the DTC with the HDS.
- Test-drive the vehicle for several minutes in D through all five gears, then slow down to a stop.
- Turn the ignition switch to LOCK (0), and repeat the test-drive in step 2.
- Check for other DTCs indicated simultaneous 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 5.
- Update the A/T software in the PCM if it does not have the latest software (see UPDATING THE PCM ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
- Test-drive the vehicle for several minutes in D through all five gears, then slow down to a stop.
- Turn the ignition switch to LOCK (0), and repeat the test-drive in step 6.
- Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu 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 9.
- 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 ECM/PCM REPLACEMENT ). If any other DTCs were indicated on step 8, go to the indicated DTCs troubleshooting.
NO - 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 6 and recheck.