What it means
The battery pack coolant control valve C circuit is detected as high by the control module. The code identifies an electrical signal condition; the exact circuit design and cause depend on the vehicle.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Valve C controls coolant flow in the high-voltage battery pack cooling circuit, and its control circuit lets the module command the valve. The module sets this code when it detects a signal above the expected range. A high-circuit fault can result from a short to battery voltage or an open valve coil, so it does not by itself mean the valve is stuck open.
Common causes
Most likely first.
- Wire shorted to B+
- Coil open
- Connector pins corroded - high contact resistance
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 review battery temperatures, valve C command, and related hybrid-system codes to understand when the high signal appeared.
- Inspect valve C wiring for pinched or chafed insulation that could contact a battery-positive supply, and check for heat or water damage at the connector.
- Look for corroded, loose, or backed-out connector pins that could interrupt the valve circuit.
- With the circuit safely isolated as specified by the manufacturer, test the harness for a short to B+ and test the valve coil for an open circuit.
- If the harness and valve pass, use the manufacturer's circuit procedure to check the module output and its connections.
Common fixes
- Clean and secure valve C connector contacts if poor contact is confirmed.
- Repair any valve C circuit wire shorted to B+.
- Replace valve C if its coil is confirmed open.
- Repair the control module circuit only if testing traces the high signal to the module.
Can I keep driving?
Avoid strenuous driving and charging if the vehicle limits power or reports a battery cooling warning, because the system may not control battery coolant flow reliably. Stop if power loss becomes severe or a high-voltage warning escalates.
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.