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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 (see GENERAL TROUBLESHOOTING INFORMATION )
  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. Slow down, and stop the wheels.
  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 (see ECM/PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ).
  6. Test-drive the vehicle with the shift lever in D, and let the transmission shift through all five gears. Slow down, and stop the wheels.
  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 (see SUBSTITUTING THE ECM/PCM ), 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 (see ECM/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 (see SUBSTITUTING THE ECM/PCM ), then go to step  6. If the PCM was substituted, go to step  1. If the HDS indicates NOT COMPLETED, go to step  6.