P0177
PowertrainFuel Systemlow severityFuel Composition Sensor Circuit Range/Performance
What P0177 Means
The fuel composition sensor reading is outside expected range.
Symptoms
- Check Engine Light
- Incorrect fueling
Common Causes
- Contaminated sensor
- Sensor calibration issue
- Mixed fuel types
Diagnostic Steps
- Compare sensor reading to known fuel type
- Test sensor output range
Where to start: Replace sensor.
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