Alternative Fuel Disable Control Circuit High
Voltage on the alternative-fuel disable control line is above the expected window. Often a short to battery upstream of the relay or a stuck-on driver in the control module.
Affected components
- Alt fuel control module
- Wiring harness
Common causes
- High likelihood: Disable control wire shorted to a B+ supply
- Medium likelihood: Output driver stuck on inside the control module
- Low likelihood: Connector pins corroded - high contact resistance
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.