Many modern vehicles use an auxiliary electric water pump in addition to the main pump. It may boost heater flow, cool a turbocharger after shutdown, or circulate coolant when the engine is stopped by start-stop systems.
Common Symptoms
- Weak heater output, especially at idle.
- Auxiliary pump fault codes.
- Overheating of the turbocharger or engine after shutdown.
- Coolant leaks at the pump body or hoses.
Diagnosis
- Check fuses, relays and the connector first.
- Command the pump on with a scan tool where supported and listen or feel for operation.
- Check for air trapped in the cooling system.
Replacement Tips
- Use the correct pump for the application.
- Fill and bleed the cooling system completely.
- Confirm operation and clear codes after the repair.
Evergreen Parts
Evergreen offers cooling system parts identified by engine or vehicle application. Use the Evergreen eCatalog to find the right part, and see where to buy Evergreen through our authorized distributors.
