OBD-II code · Powertrain (generic)
P0179 Fuel Composition Sensor Circuit High Input
The flex-fuel composition sensor signal exceeds the maximum threshold. Likely shorted to voltage, open ground or failed sensor.
Is it safe to drive with P0179?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to voltage
- PossibleSensor failed
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Flex Fuel Composition Sensor, Sensor Wiring
Related codes
- P0176Fuel Composition Sensor Circuit Malfunction
- P0177Fuel Composition Sensor Circuit Range / Performance
- P0178Fuel Composition Sensor Circuit Low Input
- P017ACylinder Head Temperature Sensor A Circuit
- P017BCylinder Head Temperature Sensor A Range/Performance
- P017CCylinder Head Temperature Sensor A Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.