What it means
Input power line C voltage below expected range. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
The module monitors its C input-power feed to confirm voltage remains high enough for operation. This code sets when the C-feed voltage is below the expected range, which may cause the module to reset or lose communication.
Common causes
Most likely first.
- Weak battery or high supply resistance
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
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
How to diagnose it
- Save freeze-frame data and scan all modules for low-voltage or communication codes to determine whether the C-feed drop was shared across the vehicle.
- Test the battery and charging system, since weak system voltage can reduce supply to the C input.
- Inspect the module’s C-feed fuse, connector, wiring, and ground for corrosion, loose terminals, or damage.
- Measure voltage at the C feed during the fault conditions and compare it with the manufacturer's specification.
- If system voltage and the C feed are sound, check supply-path voltage drop, then inspect gateway routing and CAN termination per the wiring diagram.
Common fixes
- Clean and tighten poor C-feed or ground connections.
- Replace a weak battery if it fails the manufacturer's battery test.
- Repair damaged or high-resistance C-feed wiring or terminals.
- Repair a confirmed gateway or CAN network fault if C-feed voltage is correct.
Can I keep driving?
If the module shuts down, limp mode occurs, or important functions stop working, pull over when safe and avoid continuing because vehicle capability may be reduced. If symptoms are limited, keep driving short and arrange prompt diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.