Alternative Fuel Disable Control Circuit / Open
The controller cannot drive the alternative-fuel disable line that switches a bi-fuel vehicle (CNG, LPG, hydrogen) back to gasoline. An open detected on the control side blocks the safety shutoff for the gas system.
Affected components
- Alt fuel control module
- Alt fuel disable relay
- Wiring harness
Common causes
- High likelihood: Broken wire or corroded connector on the disable control line
- Medium likelihood: Open coil in the alt-fuel disable relay
- Low likelihood: Output driver in the alt-fuel control module faulty
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.