What it means
The hybrid electronics coolant pump A reports a control circuit high condition. Power electronics cooling may be impaired.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Electronics coolant pump A circulates coolant through the hybrid or EV power electronics cooling loop. P0CEC sets when the monitored pump A control circuit voltage is higher than expected, which can result from a short to battery positive, an open motor, or a poor connector connection.
Common causes
Most likely first.
- Wire shorted to B+
- Open motor
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid or EV system warning light on
- Reduced power or limited vehicle operation
- Cooling-system warning may appear
How to diagnose it
- Review freeze-frame data and scan-tool pump A command and cooling status to establish when the high circuit condition occurs.
- With the vehicle powered down according to the manufacturer's high-voltage safety procedure, inspect the pump connector for corrosion, loose terminals, or damage.
- Inspect the pump A control wire for a short to battery positive, including at chafed or previously repaired sections.
- Test the control circuit and motor for continuity or an open condition using the manufacturer's wiring diagram and specifications.
- If the circuit tests correctly, verify the pump control output and pump operation using the manufacturer's procedure.
Common fixes
- Clean and secure corroded or poorly seated pump connector terminals.
- Repair a control wire shorted to battery positive.
- Replace pump A if its motor circuit is open.
- Repair a control-side fault confirmed by circuit testing.
Can I keep driving?
Limit driving and avoid heavy loads if a cooling warning or reduced power appears, because pump A may not circulate coolant as intended. Stop safely if power becomes restricted or the warning persists.
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.