P0DEC: Hybrid/EV Battery Pack Coolant Control Valve C Control Circuit High
What to do
Expect reduced power and slower charging, and in cold weather a car that feels flat until it has been driven a long way. It is drivable. Mention whether the symptoms are worse hot or cold — that distinction points at which position the valve is stuck in.
What this code means
The third traction battery coolant control valve is faulty.
A traction battery has a narrow temperature band it actually likes, and the coolant control valves are how the car keeps it there.
The valve routes coolant between circuits — through a chiller to cool the pack, through a heater or a warm loop to bring it up to temperature, or around the pack entirely. A third valve implies a thermal system elaborate enough to need three routes, which is typical of a car that rapid-charges, because rapid charging generates heat far faster than driving does.
The failure that costs most is the winter one, and it is counter-intuitive. A valve stuck in its cooling position pours away heat the car is trying to put into the pack, so the battery never reaches working temperature. The result is reduced power, weak regenerative braking and rapid charging refused — on a car whose cooling system is working perfectly. In a warm climate the same failure might never be noticed at all.
Note the valve is commanded on one circuit and its position reported on another, deliberately: a valve fails by sticking, and only the position feedback can see that. A control circuit that tests good proves the command was sent, not that anything moved.
At or above the upper limit, usually an open or a short to supply.
Likely causes
Start here
- Faulty battery pack coolant control valve · specialist
- Corroded or loose connector · specialist
Less common
- Open circuit in control wiring · specialist
- Control module driver failure · specialist
- Restricted coolant flow or blocked passage · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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