P1780

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. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears.
4. Turn the ignition switch to LOCK (0). Repeat the test-drive step 3, then go to step 5.
5. Check for other DTCs indicated along with DTC P1780 with the HDS.

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

Are there other DTCs?
YES - Go to the indicated DTC's troubleshooting.
NO - go to step 6.

6. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
7. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears.
8. Turn the ignition with to LOCK (0). Repeat the test-drive in step 7, then go to step 9.
9. Check for DTCs with the HDS.

Is DTC P1780 indicated?
YES - Check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 7. If the PCM was substituted, go to step 1.
NO - Go to step 1.

10. Monitor the OBD STATUS for P1780 in the DTCs MENU with the HDS.

Does the HDS indicated 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 in step 9, go to the indicated DTC's troubleshooting.
NO - If the HDS indicates FAILED, check for poor connections or loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 7. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 7.

Advanced Diagnostics