What it means
The control module monitors the return line valve control circuit for an open or electrical fault. It sets this code when the circuit does not respond as expected during a monitored command.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The alternative-fuel return line valve controls fuel flow through the return line, and the module monitors its electrical control circuit during commands. This code sets when that circuit is open or does not respond electrically, such as from a broken wire, an open valve coil, or a connector pin pushed out of position.
Common causes
Most likely first.
- Open in valve control wire
- Open valve coil
- Pin pushed back out of connector body
Symptoms
- Check-engine or alternative-fuel system warning light, if equipped
- Reduced power or poor acceleration
- Rough running or stalling
How to diagnose it
- Review freeze-frame and live data to see when the return line valve was commanded and whether reduced power or rough running coincided.
- Inspect the return line valve connector for a pin pushed back, poor latching, corrosion, or harness damage.
- Trace the valve control wire for breaks or chafing, especially where the harness bends or passes near other components.
- Test the valve coil and control wire for continuity using the wiring diagram and manufacturer’s procedure.
- If both test correctly, check the connector path to the module for an intermittent open during a monitored command.
Common fixes
- Seat a pushed-back pin and secure the return line valve connector.
- Repair an open or damaged return line valve control wire.
- Replace the return line valve if its coil is open.
- Clear the code and verify valve operation and stable engine running.
Can I keep driving?
A failed return line valve circuit can cause reduced power, rough running, or stalling. Avoid driving if the engine stalls or fuel delivery is unstable.
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.