Circuit/System Testing

WARNING: This page is about a different car, the 2008 Saturn Outlook, 2008 GMC Acadia, and 2008 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

C0131 3A or C0131 4B

Verify DTC C0131 3A or CO131 4B is not set.

If DTC is set, perform the scan tool EBCM special function, Brake Pressure Sensor Calibration. Refer to Brake Pressure Modulator Valve Replacement .

C0131 00 or C0131 5A

Apply and release brake pedal. Verify brake lamps operate properly.
- If brake lamps do not operate properly, refer to Symptoms - Lighting .
Replace the brake pressure modulator valve assembly.