P0179: Fuel Composition Sensor Circuit High
Severity
Medium
System
Fuel and Air Metering
What Does P0179 Mean?
P0179 is a diagnostic trouble code indicating: Fuel Composition Sensor Circuit High. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Symptoms of P0179
- β οΈ Check Engine Light (MIL) illuminated
- β οΈ Fuel Composition Sensor reading stuck at maximum value
- β οΈ Related system operating erratically or in default mode
- β οΈ Poor fuel economy
Common Causes
- π Short to voltage in Fuel Composition Sensor wiring harness
- π Corroded or water-damaged Fuel Composition Sensor connector
- π Faulty Fuel Composition Sensor outputting maximum voltage
- π Damaged wiring rubbing against metal components
- π ECM/PCM internal fault (rare)
Frequently Asked Questions
What does P0179 mean?
P0179 indicates: Fuel Composition Sensor Circuit High. The vehicle's computer has detected that the Fuel Composition Sensor is not operating within its expected parameters and stored this diagnostic trouble code.
Can I drive with code P0179?
You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P0179 for extended periods may cause additional problems.
How much does it cost to fix P0179?
Repair costs for P0179 typically range from $20 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80β$150 at most shops) will identify the exact cause before committing to expensive parts.
What To Do Next
Possible Fixes
- π§ Inspect and repair Fuel Composition Sensor wiring for short to voltage
- π§ Clean or replace corroded Fuel Composition Sensor connector
- π§ Replace faulty Fuel Composition Sensor
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50β$150) pinpoints the root cause.
Related Codes
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P0101
Mass or Volume Air Flow Sensor A Circuit Range/Performance
P0102
Mass or Volume Air Flow Sensor A Circuit Low
P0103
Mass Air Flow Circuit High Input
P0104
Mass or Volume Air Flow Sensor A Circuit Intermittent
P0105
Manifold Absolute Pressure/Barometric Pressure Sensor Circuit
P0106
Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Range/Performance
P0107
Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Low
P0108
Manifold Absolute Pressure/Barometric Pressure Sensor Circuit High
P0109
Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Intermittent