What it means
The HV battery pack coolant pump A runs below the calibrated minimum speed for the commanded duty. Mechanical resistance high, supply voltage low, or pump aged.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery coolant pump A circulates coolant to manage the temperature of a hybrid or electric vehicle’s high-voltage battery pack. This code sets when the pump’s reported speed is below the minimum expected for the commanded operation, which can reduce battery cooling.
Common causes
Most likely first.
- Pump wear or mechanical drag
- Low supply voltage
- Coolant flow restriction
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Record freeze-frame data and use a compatible scan tool to compare pump A’s commanded operation with its reported speed and any battery-temperature warnings.
- Check the coolant level and look for leaks or visible restrictions in the battery-cooling circuit using the vehicle’s specified procedure.
- Inspect pump A’s accessible connectors and low-voltage wiring for loose connections, corrosion, or damage without disturbing high-voltage components.
- Check pump A’s supply and ground under the commanded condition using the manufacturer’s procedure to identify voltage loss.
- If the supply is correct and coolant flow is unobstructed, test pump A’s operation and speed feedback using the manufacturer’s procedure.
Common fixes
- Restore the specified coolant level and repair any leak found.
- Repair a confirmed restriction in the battery-coolant circuit.
- Repair a loose or damaged pump A low-voltage connection or wiring.
- Replace pump A if it drags or cannot reach the required speed with correct supply.
Can I keep driving?
Treat the hybrid or EV warning as urgent: avoid hard acceleration, fast charging, and long trips, and arrange prompt diagnosis. Reduced battery cooling can lead to power limits, charging restrictions, or further battery-temperature problems.
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.