P0CE4: Hybrid/EV Battery Pack Coolant Control Valve Position Sensor Circuit

P0CE4 is the general circuit fault of the position feedback from the battery coolant control valve. On motor-driven valves the actuator reports its actual position as a share of the sensor supply voltage, letting the controller confirm that coolant really flows toward the battery, chiller or heater. GM's Volt and ELR monitor this feedback but report its electrical faults as P0CE6 and P0CE7; no manufacturer publicly documents P0CE4 itself. CARB requires battery thermal management inputs to be checked for circuit faults. Likely causes are an open signal, reference or ground wire, a damaged connector at the valve or a failed sensor inside the actuator, which is normally replaced together with the valve. Without feedback the controller may park the valve and limit charging or power. Implausible positions are P0CE5.

High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

Symptoms

MIL or hybrid system warning
Valve held in a default position, thermal conditioning limited

Most likely causes

Open signal, reference or ground wire of the position sensor
Damaged or corroded connector at the valve
Position sensor inside the valve actuator failed

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

Repair difficulty: hard
It can trigger limp mode.
It affects emissions.

What each character of P0CE4 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
C: Subsystem depends on the code range
E4: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0CE4?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0CE4?

The most common causes are: open signal, reference or ground wire of the position sensor; damaged or corroded connector at the valve; position sensor inside the valve actuator failed.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.