P0CE4

What it means

P0CE4 is a generic powertrain code for a fault in the circuit of the position sensor on the hybrid or EV battery pack coolant control valve. The control unit that manages battery thermal control saw a signal from the valve position sensor that was out of range, missing, erratic or not matching the position it commanded. Exact wording and how the fault is detected vary by manufacturer and model.

Symptoms

• Warning light on, such as the hybrid system or malfunction indicator
• Reduced power or limited acceleration from the hybrid or EV system
• Battery temperature higher than normal, or cooling fan running louder or more often
• Reduced EV range or limited charging speed
• Message about a hybrid system or battery cooling fault
• No noticeable change, with only a stored fault

Possible causes

• Damaged, corroded or loose wiring or connector at the coolant control valvelikely
• Faulty position sensor inside the coolant control valve or valve actuatorlikely
• Valve stuck or seized mechanically, so the sensor reading does not match the commanded positionpossible
• Sensor supply or reference voltage or ground fault in the circuitpossible
• Low or contaminated coolant or air in the battery cooling circuit affecting valve operationrare
• Fault in the battery thermal management control unit or its softwarerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting battery temperature and valve position at the time of the fault, and check for other thermal management or battery codes.
2. Check for manufacturer service bulletins and software updates relevant to the model and the code.
3. Visually inspect the valve wiring and connector for damage, water ingress, corrosion, chafing and poor pin tension, following the manufacturer's high voltage safety procedures.
4. Check the battery coolant level and condition, and look for leaks, following the manufacturer's procedure for the model.
5. With a scan tool, compare commanded and actual valve position and watch whether the sensor signal moves smoothly and plausibly.
6. Test the sensor supply voltage, signal and ground at the connector against the manufacturer's specification, using the wiring diagram for the model.
7. Run the valve through an actuator test if the vehicle supports it, and listen and feel for movement or sticking.
8. Check the wiring for continuity and short circuits to supply or ground between the valve and control unit.

How to fix

• Repair or replace damaged wiring and clean or replace corroded or loose connectors.
• Replace the coolant control valve or its position sensor if the readings are faulty or it is stuck, as the manufacturer specifies for the model.
• Restore correct coolant level, bleed the system and fix any leaks using the manufacturer's procedure.
• Repair the supply or ground fault found in the sensor circuit.
• Update the control unit software where an applicable update exists, or replace the control unit only if proven faulty.
• Clear the codes after repair and road test to confirm the fault does not return.

Can I keep driving?

Nearby codes

• P0CE3GenericHybrid/EV Battery Pack Coolant Control Valve A Control Circuit High
• P0CE5GenericHybrid/EV Battery Pack Coolant Control Valve Position Sensor Circuit Range/Performance