What it means
The EVAP leak detection pump remains on after it is commanded off. A fault in the pump control circuit or its driver may prevent the pump from switching off.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EVAP leak detection pump runs during tests that check whether the fuel-vapor system is sealed. The engine control module monitors whether the pump switches off when commanded. This code sets when the pump remains on, pointing to a control-circuit or driver fault that can keep the test from working correctly.
Common causes
Most likely first.
- Pump or control circuit fault
- Relay or control driver stuck on
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Record freeze-frame data and check for related EVAP codes to determine when the pump was expected to switch off.
- Check the fuel cap and inspect accessible EVAP hoses and pump connections for damage or disconnection.
- With the vehicle safely shut down, inspect the pump connector, relay, and control wiring for corrosion, shorts, or damaged insulation.
- Use a scan tool to compare the commanded pump state with its actual operation and available circuit data under the manufacturer's specified test.
- If the pump remains on with the command off, test the relay and control driver circuit to locate a stuck switching component.
Common fixes
- Repair chafed or shorted leak detection pump control wiring.
- Replace a relay that remains closed when it should switch off.
- Repair the control driver circuit if it continues to energize the pump after the off command.
- Replace the pump if testing shows an internal fault that keeps it running.
Can I keep driving?
Avoid driving if the pump is noisy continuously, the vehicle reports additional electrical faults, or you smell strong fuel; have the issue checked promptly. A pump that stays energized can overheat or fail, and the EVAP system may not pass an emissions inspection.
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.