Control Module Input Power B Circuit/Open
Open circuit on input power line B of the control module (second supply rail, e.g. permanent +12V vs switched battery feed).
Affected components
- Module power b
- Fuse
- Power wiring
Common causes
- High likelihood: Supply fuse blown
- 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.