Lost Communication with Restraints Control Module B
The Restraints Control Module B has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. A second restraints controller is unreachable, affecting airbag readiness. Safety-critical. 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
- Restraints control module
- Can bus wiring
Common causes
- High likelihood: Secondary SRS module unpowered
- Medium likelihood: CAN wiring to secondary SRS 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
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.