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DTC Troubleshooting: P1780 (49)

DTC P1780:
 Shift Control System (Transmission Default Mode)
  1. Clear the DTC with the HDS.
  1. 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.
  1. Check for other DTCs indicated simultaneously 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 4 .
  1. 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.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1780 indicated?
YES -
If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to Step 1 .
NO -
Go to Step 7 .
  1. 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. If any other DTCs were indicated on Step 6 , go to the indicated DTC's troubleshooting.■
NO -
Check for poor connections and loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to Step 1 . If the HDS indicates NOT COMPLETED, return to Step 5 and recheck.