What it means
The motor electronics coolant pump A is not meeting the expected performance monitored by the control system. The reason may involve the pump or coolant flow, and varies by vehicle.
How it works
Motor electronics pump A circulates coolant to remove heat from power electronics such as the inverter, with the exact layout varying by vehicle. The control system monitors pump A operation and cooling performance, and sets this code when the response does not meet its expected performance.
Common causes
Most likely first.
- Air in the coolant circuit
- Low coolant level
- Restricted coolant flow
- Faulty coolant pump
- Pump wiring or connector fault
Symptoms
- Hybrid or powertrain warning light
- Reduced vehicle power
- Cooling system warning
- Pump noise or overheating
How to diagnose it
- Check freeze-frame data and live cooling-system information for pump A operation, temperature warnings, and when the performance fault appeared.
- When the system is cool, check the relevant coolant reservoir level and look for leaks or signs of air in the circuit that serves pump A.
- Inspect pump A, its connector, and accessible wiring for damage, poor connections, or corrosion.
- Check for restricted hoses or flow in pump A's circuit and follow the manufacturer's bleeding procedure if air is suspected.
- If coolant level, flow, and wiring are satisfactory, test pump A operation using the manufacturer's procedure and replace it if it fails.
Common fixes
- Top up the correct coolant if low and repair any leak found.
- Bleed air from pump A's cooling circuit using the manufacturer's procedure.
- Repair a restricted hose or poor electrical connection at pump A.
- Replace pump A if its operation fails the specified test.
Can I keep driving?
If a cooling warning, overheating, pump noise, or reduced power occurs, stop safely and switch off the vehicle; continued operation can overheat motor electronics. Avoid towing or demanding driving until pump A's cooling performance is restored.
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.