DTC Troubleshooting

Control System DTCs

DTC Troubleshooting: P1780

DTC P1780 : Shift Control System (Transmission Default Mode)

NOTE:
* Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information How To Troubleshoot The A/T System.
* This code is stored whenever DTCs P1746 and P1747 are detected.

1. DTC check:

DTC check
-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. Check for other Pending or Confirmed DTCs indicated along with DTC P1780 with the HDS.
NOTE: DTC P1780 means there is one or more A/T DTCs regarding the shift control system.

Are there other DTCs?
-YES- Go to the indicated DTC's troubleshooting.
-NO- There are no DTCs along with DTC P1780. Update the PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good PCM Service and Repair, then do the repair verification.

Repair verification (OBD STATUS check):

-1. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears.

-2. Monitor the OBD STATUS for P1780 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
-PASSED- Troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.
-FAILED- Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM Service and Repair, and check the OBD STATUS again.
-NOT COMPLETED- Meet the test condition, and check the OBD STATUS again.