What it means
The control module detects that alternative-fuel tank shutoff valve A is not responding as expected. The cause may be electrical or mechanical, depending on the system.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Alternative-fuel tank shutoff valve A opens or closes to control fuel flow from the tank. The control module checks whether the valve responds as commanded; this code sets when the valve appears not to move or operate as expected, including when it is stuck closed.
Common causes
Most likely first.
- Valve seized closed
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Alternative-fuel system may not operate
How to diagnose it
- Check freeze-frame data and alternative-fuel system codes to confirm when the module detected that valve A failed to respond.
- Inspect valve A and its connectors for visible damage, contamination, loose wiring, or signs that the valve cannot move freely.
- Use a scan tool’s supported output test, if available, to command valve A and observe whether its reported state or system response changes.
- Check the valve’s control circuit and electrical supply for opens, shorts, or poor connections using the wiring diagram and manufacturer’s procedure.
- If the circuit is sound, test the valve for sticking or restricted movement and compare its operation with the manufacturer’s procedure.
Common fixes
- Clean accessible debris from valve A if the manufacturer permits cleaning.
- Repair a loose or damaged connector or wire in the valve A control circuit.
- Replace valve A if it is seized closed or does not respond despite a sound circuit.
- Replace a worn valve assembly if mechanical play prevents reliable operation.
Can I keep driving?
The vehicle may be drivable on its other fuel system, but alternative-fuel operation may be unavailable. Do not force or bypass the shutoff valve; a stuck valve can prevent proper fuel isolation.
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.