What it means
EVAP System Purge Control Valve B Performance Stuck Open: the component is electrically intact but its response does not match the command.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EVAP purge control valve B opens and closes to meter fuel vapor from the charcoal canister into the intake. P04AE sets when the module's electrical command appears present but the valve does not respond as expected, often because it cannot close fully and continues passing vapor.
Common causes
Most likely first.
- Debris on valve seat prevents full closing
- Return spring weakened
- Carbon or debris buildup preventing free movement
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
- Review freeze-frame and EVAP live data for purge valve B command and the system's response when the module requests it to close.
- Inspect valve B's connector and hose connections for damage, looseness, or contamination that could affect its operation.
- Use the scan tool's available output controls to command valve B open and closed, checking whether the EVAP response changes accordingly.
- Check whether valve B allows flow when it should be closed, using the manufacturer's test procedure.
- If wiring and command response are sound, inspect valve B for debris on its seat or a weakened return mechanism.
Common fixes
- Reconnect or secure loose valve B hoses or electrical connections.
- Clean the valve seat if the manufacturer's procedure permits and debris is present.
- Replace purge valve B if it continues to pass vapor when commanded closed.
- Repair any wiring fault found during command and response checks.
Can I keep driving?
Short trips are generally possible if the vehicle runs smoothly, but avoid delaying repair if there is a fuel-vapor smell or rough running. A valve that does not close can disrupt EVAP leak checks and increase emissions.
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.