How to Change a Fuel Level Sensor

An empty gas gauge with the fuel light on.

A fuel level sensor (or gasoline gauge) is a device utilized to show the amount of gasoline remaining in a vehicle tank. While widely used in automobiles, these devices can also be useful for any reservoir such as underground storage container tanks. It is possible to change your vehicle fuel level sensor without consulting a car dealership. A professional will charge you around $450 to install a fuel sensor, but you can do it yourself at a cost lower than $100.

How Does it Work?

In vehicles, the device is made up of two components: the sensor system and the fuel indicator. The sensor device often runs on the float attached to a potentiometer. When the vehicle tank runs dry, the float falls and turns a shifting connection over the resistor, maximizing its resistance. Furthermore, as soon as resistance reaches a specific level, it is going to also switch on a low gas light on certain cars.

At the same time, the fuel indicator system (often installed on the dash panel) is calculating as well as showing the volume of electric current passing through the transmitting system. As soon as fuel volume is increased and optimum electric current is passing, the gauge reads (F), showing a 100 percent full car tank. If your tank is dry and the minimum electric current is moving, the gauge reads (E), showing a dry tank.

Step 1 – Close the Gas and Power Lines

Remove negative battery cable. Raise the rear hatch or open the trunk and take out the spare tire if you have one. Detach gas as well as electric power cables to the fuel tank.

Step 2 – Detach the Tank

Unclip the electrical cables using a pair of small screwdrivers, and remove the tank holders. Take out three bolts on the bearers that support the tank under the vehicle as well. Then, gradually move vehicle's gas tank down (a smaller amount of gasoline makes the tank lighter to hold). You can ask a friend to help you to hold the tank, with each person on either end.

Step 3 – Remove Transmitting Device

Remove the clips on the electrical attachment at the top of transmitting device (you should not detach the gas pipe at this time because fuel will come out from the tank). Next, using a screwdriver and hammer, rotate the lock ring at the top of the transmitting device to line up the lock tabs and channels. Spray the lock ring with lubricating oil while removing it to minimize the friction when it spins. Once the lock ring is off, take the transmitting device out of the gas tank.

Step 4 - Remove Fuel Level Sensor

Locate the fuel level sensor, which is often situated on the very bottom part of the transmitting device. Remove the clip from the harness and slide off the sensor.

Step 5 – Fit New Sensor

When you purchase a new fuel level sensor, be sure to consult with your vehicle's owner's manual, or with a store associate, to make sure you're buying the right part.

Install a new gas level sensor by sliding it into the old one's place. Repeat these steps from the last to the first in reverse to replace the unit in the vehicle tank and you are finished. It will require roughly two hours to reassemble.

Note: When there is insufficient space to access the transmitting unit, you must decrease the volume of fuel in the tank first to reach the top. Decrease the tank fuel volume to roughly 1/4 tank of gasoline.