Communication Bus "C" Off
A control module has detected that bus C is non-functional and shut its bus C interface off. Bus C is typically a tertiary segment used for diagnostics or specialized subsystems; modules on the segment fall silent simultaneously.
Affected components
- Can bus wiring
- Control module
Common causes
- High likelihood: Bus C shorted to supply or ground
- Medium likelihood: One failing module pulling bus C down
- 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.