Lost Communication with Brake System Control Module
The Brake System Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. ABS and electronic brake functions are lost; base braking remains but the assists are off. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
Affected components
- Brake system control module
- Can bus wiring
Common causes
- High likelihood: Brake module unpowered
- Medium likelihood: CAN wiring to brake module broken
- Low likelihood: Gateway module routing CAN messages incorrectly
Possible symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Diagnostic notes
- The malfunction indicator lamp may illuminate
- Reduced-power or limp mode may occur
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.