Lost Communication with Vehicle Immobilizer Control Module
The ECU cannot reach the immobilizer / vehicle security module. Engine start is usually blocked because the rolling code cannot be exchanged.
Affected components
- Immobilizer module
- Can bus wiring
Common causes
- High likelihood: Immobilizer module unpowered
- Medium likelihood: Wiring or antenna ring damaged
- 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.