Error Code P0462 is defined as Fuel level Sensor Circuit Low Input, which means the fuel level sensor is no longer taking correct readings.

This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II, especially those made from 1996 up to the present. It is, however, more common among Chrysler, GM, Ford, Lincoln, Mercury, Kia, Mazda, Mercedes Benz, Infiniti, Nissan and Subaru vehicles. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

Definition

The fuel level sensor (also known as sender) is an essential component of the fuel pump module and located in the fuel tank. This component can’t be replaced without replacing the pump module, though there are some exceptions. Attached to the arm is a float that travels with a resistor grounded to the tank, frame or a dedicated ground circuit. The sender receives a supplied voltage, and the ground path changes according to the level of fuel. The amount of voltage depends on the system, but in many times it’s around 5V.

As the fuel level changes, the float moves the arm, changing the resistance to ground which varies the voltage signal. This signal will either go straight to the fuel pump computer module, or to the instrument cluster module. Depending on the vehicle’s system, the fuel pump computer module may only monitor the resistance to ground, and then relay the fuel level information to the instrument panel. If the fuel level sensor is sending wrong voltage readings that the PCM deemed to be too low to be accurate, then the Error Code P0462 will be set.

Other related Error Codes include:

Common Symptoms

As with other error codes, this code activates the Check Engine light as its first symptom.

Common symptoms include:

  • Incorrect fuel level on gauge in instrument cluster – always reads wrong
  • Erratic fuel gauge
  • Decrease in perceived fuel economy
  • Decrease in distance to Empty mileage

Possible Causes

Common causes for this code include:

  • Open in the signal circuit to the FLS sensor
  • Damaged fuel tank
  • Fuel level sensor has suffered an opening
  • Open ground circuit
  • Rusty ground path causing high resistance
  • Short to voltage in the signal circuit to the FLS sensor
  • Short to ground in the signal circuit to the FLS sensor
  • Failed FLS Sensor/sensing arm stuck mechanically
  • Failed PCM (rare)

How to Check

Error Code P0462 is quite a simple problem, and as with other Error Codes, diagnosis for this code starts with the use of OBD-II scanner; mechanics look for codes that have been logged in the vehicle’s PCM.

Technicians will also check the tank from the outside and look for signs of damage that could be leading to poor readings.

Given that this code is a voltage problem, technicians will inspect the circuitry related to the fuel level sensor responsible for sending wrong readings to the PCM.

Lastly, technicians will test the sensor itself.

How to Fix

Common repairs for this code include:

  • Sealing of the fuel tank, or replacement
  • Replacement of the entire fuel level sensor or malfunctioning element
  • Replacement of broken or frayed wires

One of the most common mistakes when addressing this problem is looking at a single issue and leaving other possibilities. For example, the fuel tank may be damaged, and that may be causing a bad reading, but code P0462 is wrong with the voltage. Thus, the problem with the tank must be fixed, but technicians must continue his diagnosis to look for other causes.

Though this code doesn’t cause serious safety concerns or drivability problems, not knowing how much gas you have on your vehicle can cause quite a hassle if you run out of gas on the road.