Lost Communication with Body Control Module
CAN messages from the body control module (BCM) are missing. Effects depend on what the BCM controls — typically interior lights, wipers, central locking, immobiliser handshake. On some cars the engine refuses to start because the immobiliser handshake fails.
Affected components
- Body control module
- Can bus wiring
Common causes
- High likelihood: BCM unpowered
- Medium likelihood: Water ingress into BCM (often footwell-mounted)
- 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
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.