Brake System Control Module A Requested MIL Illumination
The primary brake system control module (ABS/ESC/iBooster) has requested the ECM to illuminate the MIL because of an emissions-relevant fault on its side — for example a regenerative braking fault on a hybrid that affects driveline torque flow. The original fault is in the brake module.
Affected components
- Brake control module a
Common causes
- High likelihood: Internal fault in the brake module — read its DTCs
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.