P0179 2018 Chevrolet Silverado Code - Fuel Composition Sensor Circuit High Frequency
Quick Answer
The Fuel Composition Sensor (FCS), or Flex Fuel Sensor (service parts term), measures the ethanol-gasoline ratio of the fuel being used in a flexible fuel vehicle. Common causes include Faulty Fuel Composition Sensor (FCS) or Flex Fuel Sensor, Fuel Composition Sensor harness is open or shorted, Fuel Composition Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0179 2018 Chevrolet Silverado indicates Fuel Composition Sensor Circuit High Frequency.
- Common causes
- Common causes include Faulty Fuel Composition Sensor (FCS) or Flex Fuel Sensor, Fuel Composition Sensor harness is open or shorted, Fuel Composition Sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0179 2018 Chevrolet Silverado Description
Alcohol content information is supplied to the Engine Control Module (ECM) from the Fuel Composition Sensor. The Fuel Composition Sensor has an ignition positive circuit, a signal circuit, and a ground circuit. The Fuel Composition Sensor uses a microprocessor inside the sensor to measure the ethanol percentage and changes the output signal accordingly. The signal circuit carries the ethanol percentage via the frequency signal. The ECM provides an internal pull up to 5V on the signal circuit, and the fuel composition sensor pulls the 5V to ground in pulses. The normal range of operating frequency is between 50 - 150 Hz. The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency between 180 Hz and 190 Hz indicates that the fuel is contaminated. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the fuel composition sensor output frequency is less than 45 Hz for greater than 6s.
What are the Possible Causes of the DTC P0179 2018 Chevrolet Silverado?
- Faulty Fuel Composition Sensor (FCS) or Flex Fuel Sensor
- Fuel Composition Sensor harness is open or shorted
- Fuel Composition Sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0179 2018 Chevrolet Silverado?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0179 2018 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0179 2018 Chevrolet Silverado Code
1. What does the OBDII code P0179 mean on a 2018 Chevrolet Silverado?
P0179 indicates that the fuel composition sensor circuit is detecting a high frequency, which suggests an issue with the sensor or its wiring related to fuel ethanol content measurement.
2. What are the symptoms of a P0179 code in a 2018 Chevrolet Silverado?
Common symptoms include a check engine light, poor fuel economy, rough idling, reduced engine performance, or difficulty starting the vehicle.
3. What causes the P0179 code in a 2018 Chevrolet Silverado?
Potential causes include a faulty fuel composition sensor, damaged or corroded wiring, a poor electrical connection, or a malfunctioning ECM (engine control module).
4. Can a dirty fuel system trigger the P0179 code on my Silverado?
Yes, contamination in the fuel system, such as water or debris, can sometimes interfere with the fuel composition sensor and trigger this code.
5. How do I diagnose a P0179 code on a 2018 Chevrolet Silverado?
Start by inspecting the wiring and connectors for damage or corrosion, check the fuel composition sensor for proper operation, and verify the ethanol content in the fuel using diagnostic tools.
6. Can I drive my 2018 Chevrolet Silverado with a P0179 code?
While the vehicle may still be drivable, continuing to drive with this code could lead to poor performance or damage to the engine over time, so it’s best to address it promptly.
7. How is the P0179 code fixed on a 2018 Chevrolet Silverado?
Repairs may include replacing the fuel composition sensor, repairing damaged wiring or connectors, or reprogramming the ECM if necessary.
8. How much does it cost to repair a P0179 code on a Chevrolet Silverado?
Repair costs can vary but generally range from $150 to $400, depending on whether the issue lies with the sensor, wiring, or additional components.
9. Can bad fuel cause the P0179 code in a 2018 Silverado?
Yes, using substandard or improperly blended fuel with the wrong ethanol content can cause the fuel composition sensor to misread and trigger the P0179 code.
10. Is a P0179 code common in the 2018 Chevrolet Silverado?
While not extremely common, this code can occur, especially if there are issues with the fuel system, sensor, or wiring in vehicles designed to handle flex-fuel.
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