What it means
The BMS detects a circuit intermittent/erratic fault on voltage sense channel C of the high-voltage battery. Cell-group voltage measurement is unreliable on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery management system expects a steady voltage reading from cell group sense channel C. This code sets when the channel C signal changes unpredictably or drops in and out, which can point to an intermittent connector or wire fault.
Common causes
Most likely first.
- Loose or corroded connector
- Damaged wiring with an intermittent connection
- Fault in the battery voltage-sensing module
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Save freeze-frame data and monitor live channel C voltage alongside neighboring groups for abrupt jumps or dropouts.
- With the vehicle powered down using the manufacturer’s high-voltage safety procedure, inspect channel C wiring and connectors for chafing, corrosion, loose seating, or damage that could move with vibration.
- Check accessible channel C terminals for looseness or corrosion that could interrupt the signal.
- Have a qualified technician test channel C continuity and signal stability using the manufacturer’s procedure and approved harness checks.
- If the connection remains stable, have the battery voltage-sensing module checked for an intermittent channel C fault.
Common fixes
- Reseat or clean a loose or corroded channel C connector.
- Repair damaged or chafed channel C wiring causing an intermittent connection.
- Restore a poor terminal or splice connection in the channel C sense circuit.
- Replace or repair the battery voltage-sensing module if testing confirms an intermittent fault.
Can I keep driving?
If reduced power, limp mode, or charging trouble occurs, avoid unnecessary driving because the fault may recur and restrict the vehicle. Keep away from high-voltage battery wiring 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.