What it means
The battery pack coolant control valve C circuit is detected as low 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 is an electrically controlled valve in the high-voltage battery pack coolant circuit. The control module monitors the valve's control circuit and detects a signal below the expected range. This low-circuit fault points to an electrical problem, such as a short to ground, rather than proving that the valve is mechanically stuck.
Common causes
Most likely first.
- Wire shorted to ground
- Coil internal short
- 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 check battery temperatures, valve C command, and any related hybrid or coolant-control codes before clearing anything.
- Inspect valve C's connector and harness for corrosion, moisture, crushed insulation, or a wire rubbed through to ground.
- Check connector pin fit and condition, especially for corroded contacts or pins pushed out of the connector body.
- With the circuit isolated according to the manufacturer's service information, test for an unintended short to ground and check the valve coil for an internal short.
- If the wiring and coil pass, follow the manufacturer's circuit test to check the control module's output.
Common fixes
- Clean and secure valve C connector contacts if corrosion or poor contact is confirmed.
- Repair wiring shorted to ground in the valve C circuit.
- Replace valve C if its coil is confirmed shorted.
- Repair the control module driver only if circuit testing identifies it as the source of the low signal.
Can I keep driving?
Limit driving and avoid charging if the vehicle shows reduced power or a battery cooling warning, since the fault can prevent reliable control of battery coolant flow. Stop if power drops sharply or the hybrid/EV system 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.