What it means
The feedback signal that confirms the alt-fuel disable command was carried out is missing or out of range. The fuel system cannot verify that the gas circuit is shut.
At a glance
- Usually lights the check-engine light
How it works
The alternative-fuel disable signal circuit returns feedback so the control module can verify that the disable command was carried out. This code sets when that feedback is missing or unusable, so the module cannot confirm that the alternative-fuel circuit has shut down as commanded.
Common causes
Most likely first.
- Open feedback wire between relay and control module
- Feedback contact in the disable relay corroded or stuck
Symptoms
- Alternative-fuel operation may be unavailable
- Engine may switch to or remain on the other fuel
How to diagnose it
- Use a scan tool to record freeze-frame data and compare the disable command with its feedback status to confirm when the response goes missing.
- Inspect the feedback wire between the disable relay and control module for breaks, damage, or a loose connection.
- Check the relay connector and feedback contacts for corrosion, poor pin fit, or signs that the contact is stuck.
- With the circuit isolated as specified by the manufacturer, test continuity of the feedback wire from the relay to the module.
- If the wiring is intact, check the disable relay's feedback contact operation using the manufacturer's procedure.
Common fixes
- Reconnect or repair a loose or broken feedback wire.
- Clean or repair corroded relay or module connector terminals.
- Replace a disable relay with a stuck or faulty feedback contact.
- Repair the control module only if its feedback input is confirmed faulty.
Can I keep driving?
The engine may be unable to use the alternative fuel or may remain on the other fuel because the system cannot confirm the disable action. Avoid relying on alternative-fuel operation until checked, and stop if you notice fuel leakage or unsafe engine operation.
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.