Skip the auto shop - Our mechanics make house calls

P0176 OBD-II Trouble Code: Fuel Composition Sensor Circuit

Check Engine Light

P0176 code definition?

Fuel Composition Sensor Circuit Malfunction

What the P0176 code means

Trouble code P0176 is triggered by the Engine Control Module (ECM) when it receives an abnormal signal from the flex fuel sensor.

The flex fuel sensor is designed to measure the amount of ethanol present in the gasoline of a flexible-fuel vehicle (FFV); some ethanol is added to the gasoline because it is a renewable resource, and it burns off less pollutants. The flex fuel sensor sends a signal to the ECM in correlation with the amount of ethanol present, then the ECM adjusts the ignition timing and fuel injector pulse width accordingly.

What causes the P0176 code?

  • Contaminated or incorrect fuel
  • Faulty flex fuel sensor
  • Open or short in flex fuel sensor circuit
  • Faulty ECM
  • Damaged flex fuel sensor line

What are the symptoms of the P0176 code?

  • The Check Engine Light will set
  • The engine may stall

How does a mechanic diagnose the P0176 code?

  • Inspects the quality and clarity of the gasoline
  • Tests the circuit of the flex fuel sensor with a digital multimeter
  • Inspects the wiring and electrical terminals of the flex fuel sensor
  • Inspects the fuel lines
  • Checks the fuel pressure

Common mistakes when diagnosing the P0176 code

Not checking for fuel flow restrictions

How serious is the P0176 code?

May cause the engine to stall, which may leave you stranded or having to wait for assistance

What repairs can fix the P0176 code?

  • Exchanging of contaminated or incorrect fuel
  • Replacing a faulty flex fuel sensor
  • Repairing an open or short in the flex fuel sensor circuit
  • Replacing a faulty ECM
  • Replacing a damaged or pinched flex fuel sensor line

Need help with a P0176 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem What the P0121 code means P0121 is a generic OBD-II code which indicates that the Engine Control...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...


Related questions

Q: My car just shut off while driving nd wont start bsk up dosent even crank over nothing at all turns on

Without additional detail, this would be tough to diagnose, however the fact that it just shut down out of nowhere as you've described suggests that some kind of sensor or relay may have triggered this. I would suggest having an...

Q: Getting error code P0304

P0304 means the engine computer has detected a severe misfire on cylinder 4. This could be due to a bad ignition coil, spark plug, fuel injector, or valve train issue. If the issue is not resolved, further damage to the...

Q: Tranny troubles

You need to have the transmission leak from the bell housing fixed. The fluid leaking is causing the transmission shift problem. The trouble code P2271 indicates that the O2 sensor after the converter shorted rich. This may happen if transmission...