What it means
The motor electronics coolant pump C (cooling the drive inverter or motor) reports a control circuit low 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
Motor electronics coolant pump C circulates coolant for the drive inverter or motor electronics. The hybrid control module monitors its control circuit and sets this code when the circuit signal is lower than expected, which may indicate a short to ground or a pump motor fault and can impair cooling.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in pump motor
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid-system warning light or message
- Reduced power
- Power electronics overheating warning
How to diagnose it
- Record freeze-frame data and check live data for pump C's command, status, motor-electronics temperature, and any overheating warning.
- With the vehicle cool, inspect pump C's accessible wiring for chafing to ground and check the connector for corrosion, looseness, or heat damage.
- Check the cooling circuit for low coolant or visible leaks using the vehicle's service information.
- Following the manufacturer's diagnostic and safety procedure, test the control wire for a short to ground and the pump motor for an internal short against the manufacturer's specification.
- Repair the confirmed circuit or pump fault, then command pump C on and verify cooling-system operation.
Common fixes
- Repair a pump C control wire shorted to ground.
- Clean or repair corroded connector pins at pump C.
- Replace pump C if its motor is confirmed internally shorted.
- Restore coolant level and repair a leak if the inspection identifies a cooling-circuit loss.
Can I keep driving?
The inverter or motor electronics may overheat, causing reduced power or shutdown. Avoid driving with an overheating warning and stop safely if it appears.
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.