Circuit/System Testing

WARNING: This page is about a different car, the 2018 Buick Regal TourX and 2018 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.
Verify that DTC C025E is not set.
- If the DTC is set
  Refer to DTC C025E .
- Go to next step: If the DTC is not set
Verify that the brake booster vacuum system has no damage, leakage or incorrect installation.
- If damage, leakage or incorrect installation is found
  Refer to Brake Assist System Diagnosis .
- Go to next step: If the inspection is OK
Replace the B19B Brake Booster Vacuum Sensor.
Verify the DTC does not set while operating the vehicle under the Conditions for Running the DTC.
- If the DTC sets
  Replace the K17 Electronic Brake Control Module.
- Go to next step: If the DTC does not set
All OK.