DTC Troubleshooting

DTC Troubleshooting: P1780 (49)

DTC P1780: Problem in Shift Control System

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information. How to Troubleshoot A/T Systems

1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

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. Then slow down to a stop.

4. Check for Pending or Confirmed DTCs with the HDS.
NOTE: DTC P1780 means there is one or more A/T DTCs stored for the shift control system.

Are there other DTCs?
YES - Refer to the troubleshooting as indicated by the DTC.

NO - Go to step 5.


5. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Initial Inspection and Diagnostic Overview

6. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears. Then slow down to a stop.

7. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1780 indicated?
YES - If the PCM was updated, substitute a known-good PCM, Initial Inspection and Diagnostic Overview then go to step 6. If the PCM was substituted, go to step 1.

NO - Go to step 8.


8. Monitor the OBD status for P1780 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. PCM Replacement If any other DTCs were indicated in step 7, 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, Initial Inspection and Diagnostic Overview then go to step 6. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 6.