Fuel Fill Door Open Request Sensor or Switch Circuit Low
Same as P04C8 with the signal voltage shorted to ground or constantly low. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Fuel fill door request switch
Common causes
- High likelihood: Signal shorted to ground
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Harness chafing through insulation
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.