What it means
The control module detects a high signal in the hybrid/EV battery pack voltage sense C circuit.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The battery management module monitors voltage sense channel C for the hybrid or EV battery pack. P0B1C sets when the C-channel signal is higher than expected, which may occur if the wire is shorted to voltage, the circuit is open, or a connection is poor.
Common causes
Most likely first.
- Signal wire shorted to voltage
- Open sensing circuit
- Poor electrical connection
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
- Capture freeze-frame data and compare channel C live voltage with other pack-sense channels to confirm the high reading and its operating conditions.
- Check for other voltage-sense codes that could indicate a shared harness, connector, or monitoring-module fault.
- Inspect the channel C connector and wiring for open or backed-out terminals, corrosion, damaged insulation, or contact with a voltage source.
- Follow the manufacturer's wiring information to check channel C for an open circuit or short to voltage and verify continuity and connections to specification.
- If the harness checks out, have the channel C sensing component and battery monitoring hardware assessed with high-voltage safety precautions.
Common fixes
- Reseat or repair a loose channel C connector.
- Repair wiring that is shorted to voltage or has an open connection.
- Replace a corroded or damaged channel C connector or harness section.
- Replace a confirmed faulty sensing component or battery monitoring module.
Can I keep driving?
The vehicle may reduce power or restrict charging, so avoid relying on full electric performance or taking a long trip. Stop safely if power becomes severely limited or a high-voltage warning appears.
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.