Vehicle Communication Bus A (-) Open
The communication bus A low-side line (CAN-L) is open — broken wire, unplugged connector, or terminator missing.
Affected components
- Bus a wiring
- Bus a terminator
Common causes
- High likelihood: CAN-L wire broken or unplugged
- Low likelihood: Gateway module routing CAN messages incorrectly
- Low likelihood: CAN terminating resistor (120 Ω) drifted out of spec
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
Related codes
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.