Alternative Fuel Control Module System Voltage
The alternative fuel control module reports a system voltage out of operating range. CNG, LPG, or hydrogen fuelling can be disabled until voltage is in spec.
Affected components
- Alt fuel control module
- Charging system
Common causes
- Medium likelihood: Weak battery sags voltage under load
- Medium likelihood: Alternator output out of regulation
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.