Common Symptoms of a Faulty Fuel Level Sensor

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The Fuel Level sensor is located in your vehicle’s fuel tank. Its primary purpose is to gauge the level of fuel in the tank. Its core element is the potentiometer linked to a float. As the fuel level fluctuates, so does the float's position, resulting in a proportional shift in the resistance of the potentiometer. If the sensor malfunctions, you will not be able to accurately determine the amount of fuel remaining in the fuel tank. This can result in unexpected depletion, potential damage to the engine and even hazardous circumstances for you while driving.

This article highlights the typical symptoms of a faulty Fuel Level sensor, to help you identify potential issues and their root causes.

What Causes Fuel Level Sensor Failures?

Physical Damage: Corrosion, high levels of vibration in the road, and improper handling during maintenance cause physical damage to the sensor and prevent it from functioning properly.

Electrical Issues: A loose or damaged wire can disrupt communication between the sensor and the Engine Control Module (ECM), leading to inaccurate readings.

Contamination: The accumulation of debris, dirt, or sediment in the fuel tank can interfere with the operation of the fuel level sensor and cause incorrect readings or blockages in the float mechanism.

Wear and Tear: Over time, the fuel level sensor can experience wear and tear due to continuous exposure to fuel and other environmental factors, limiting its lifespan, and eventually resulting in failure.

Common Symptoms of the Faulty Fuel Level Sensor

Malfunction Indicator Light (MIL) or Check Engine Light (CEL) Illuminates

A malfunctioning Fuel Level sensor may trigger the vehicle's onboard diagnostics (OBD) system to illuminate the MIL and store a corresponding Diagnostic Trouble Code (DTC) in its memory. However, the MIL can illuminate for various issues, so your vehicle needs to be checked using a scan tool to determine the cause.

Erratic Fuel Gauge Behavior

When the Fuel Level Sensor malfunctions, it can continuously or intermittently send wrong information about the fuel level to the ECM. This information is the input signal for the display on the fuel gauge. As a result, the fuel gauge shows varying fuel levels or fluctuates rapidly. It may jump from full to empty or show inconsistent readings while driving.

Fuel Gauge Stuck

When the fuel level sensor does not send a signal or sends an inaccurate signal to the ECM, the fuel gauge remains stuck on a particular level for a prolonged period, typically remaining stuck in the full or empty position. This condition often occurs when the float is defective, and may result in unexpectedly depleting fuel or the inability to determine the actual fuel level.

Identify a Faulty Fuel Level Sensor with the Innova Scan Tool

The Innova Scan Tool quickly retrieves and identifies existing Diagnostic Trouble Codes stored in your vehicle’s computers. With a quick OBD2 Scan, you can retrieve existing DTCs, the I/M Status of the vehicle, and any collected Freeze Frame data from these computers. Refer to the Innova Coverage Checker to determine the level of information supported on your particular vehicle by year, make and model. The Innova Scan tool effectively diagnoses Fuel Level sensor-related issues, helping you easily pinpoint and resolve problems.

Additionally, the Innova Scan Tool lets you view Live Data PIDs and presents OEM Enhanced Live Data, with advanced information for complete vehicular diagnostics. You can also read the Fuel Level Input value with the Innova Scan Tool to determine if the Fuel Level Input value matches with the actual fuel level or if it changes after many movements. The normal operating value of the fuel level sensor depends on your vehicle.

Please visit us at innova.com/support or pro.repairsolutions.com/Support for additional information.

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