Fuel Gauge Sender Symptoms & Replacement Cost

fuel gauge level sensor

The fuel gauge sensor is a sensor that is not seen very often.

This is mainly due to the fact that it is not located near the engine under the hood, which is the area you inspect most often. This sensor is located inside the fuel tank near the fuel pump.

Signs of a Bad Fuel Gauge Level Sensor & Wirings

fuel gauge sensor

If you have a problem with the sensor of the fuel gauge or wiring, there are several symptoms that you can check to see if it is really a problem with the sensor and nothing else. Here is a list of the most common symptoms associated with a bad fuel gauge sensor.

1. Fuеl Gаugе Behaves Erratically

The first and most common symptom of a faulty fuel gauge transmitter is that the fuel gauge behaves irregularly and is not related to the actual fuel level. It can go from full to empty and back in a short space of time. If this is the case, you most likely have a problem with the fuel level sensor, the fuel gauge, or the wiring in between.

2. Fuel Gаugе Stuck On Еmрtу/Full/Middle

Anоthеr соmmоn ѕуmрtоm оf a fаultу fuеl sensor іѕ a gаugе thаt іѕ ѕtuсk on еmрtу, full or fixed in the middle. The float of the fuel gauge transmitter can often get stuck if it was previously mounted incorrectly, and in these cases, the fuel gauge can also get stuck at a certain fuel level. Most often the fuel gauge will get stuck in the bottom because the float may not float up after refilling with fuel.

3. Dесrеаѕеd or Increased Gas Mileage

This is another type of symptom you will have if you have a bad fuel transmitter. The engine control unit or instrument cluster sometimes collects information from the fuel sensor to calculate how far you can drive before refuelling, and calculates the fuel per mile. In this case, if your fuel gauge sends incorrect information, the engine control unit or instrument cluster may go crazy and give you really unrelated values for miles per gallon or how far you can drive before you need to refuel. If the fuel gauge jumps a lot, you will most likely also get erratic distance-to-refuel information.

What is a Fuel Gauge Sensor?

The sensor has a floating arm that senses the level of fuel in the tank. The fuel gauge transmitter then sends the information directly to the instrument cluster and fuel gauge. In some cases the information is first calculated in the engine control unit before it is sent to the fuel gauge.

If you have problems with the fuel gauge, you can measure the ohms of the fuel gauge transmitter at a certain fuel level and compare them with the values given in your repair manual for your specific vehicle. Perform the same procedure, measure from the fuel gauge and check that you get the same results to see if there is a wiring problem.

How do I check the fuel gauge sensor?

Checking the fuel sensor can be somewhat difficult because it is located inside the fuel tank. How difficult it is depends on the car model you have. Normally you can measure the wiring at the fuel gauge and at the connection gap at the top of the tank. Often you will find these wires under the trunk or under the back seat. You will need to find a wiring manual to find the correct wires on your fuel gauge and the correct ohm for a particular fuel level.

The fuel gauge sensor usually has two wires leading to the fuel gauge. Check for corrosion in the connections and make sure the lines are not damaged by measuring them or inspecting them with your eyes.

The most correct way to check the fuel gauge sensor is to lift it off the fuel tank and measure the ohmic value with a multimeter and make sure that the ohmic values change as you either raise or lower the float. Again, check your repair manual for the correct ohm value for your particular vehicle.

It is really easy to install the fuel gauge sensor incorrectly when you put it back in your car and this will result in incorrect values on the fuel gauge. So be very careful when installing the new fuel gauge sensor and make sure that the arm can move freely from top to bottom.

Fuel Gаugе Sender Replacement Cost

The average cost of replacing the fuel gauge sensor is about $300 to $800. The price can vary greatly depending on the model of your car due to the different types of sensors. Often it is not the sensor itself that is the expensive part, but the labor costs, due to the sensor’s location.

The sensor itself often costs less than $100, but the work can take several hours. If you do the work yourself, you can get the job done much cheaper than leaving it to your mechanic, but remember that it is not an easy task for a beginner. To replace the fuel gauge transmitter, you must reach the connector where the fuel pump is located on the fuel tank. Most likely you will find it under the back seat or in the trunk. On some cars this “service place” does not exist and you have to remove the whole tank, which makes even more work and it is recommended to empty the tank before working. Remember to use safety accessories and provide good ventilation for such work.

If you do not want to do the work yourself at home, you should visit different car dealerships and compare prices. If you have any further questions about the fuel gauge sensor, simply comment below.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.