Circuit/System Verification

WARNING: This page is about a different car, the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.

NOTE:

Refer to Liftgate System Diagnosis for a guide to power liftgate functions and failure modes to determine the course of action when the power liftgate malfunctions

Verify no other DTCs are set.
- If other DTCs are set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If no other DTCs are set
Verify the correct calibration software has been programmed into the K39 Liftgate Control Module.
- If the software is not the correct calibration software
  Refer to Control Module References for liftgate control module programming and setup.
- Go to next step: If the calibration software is correct
Verify the liftgate will release and smoothly power open when commanding Liftgate Open with a scan tool.
- If the A23C Liftgate Latch Assembly does not release
  Refer to Liftgate Latch Release/Cinch Malfunction
- If the liftgate releases but does not open
  Refer to Circuit/System Testing - Liftgate Power Open/Close Malfunction
- If the liftgate releases but performs an erratic power open/close motion
  Refer to Circuit/System Testing - Liftgate Erratic Operation
- Go to next step: If the A23C Liftgate Latch Assembly releases
Verify the liftgate will smoothly power close when commanding Liftgate Close with a scan tool.
- If the liftgate does not power close
  Refer to Circuit/System Testing - Liftgate Power Open/Close Malfunction
- If the liftgate performs an erratic open/close motion
  Refer to Circuit/System Testing - Liftgate Erratic Operation
- Go to next step: If the liftgate does smoothly power close
All OK.