Of course, it is unpleasant to drive while the gasoline gauge is erroneous. In this article, we are going to cover the most frequent reasons for car fuel gauge not working and the possible way to fix this problem.
You largely rely on your car’s fuel gauge to accurately indicate when you need to refuel while you are driving. Without it, you would have to rely on the car’s fuel capacity to bring you home. You need to be aware of the causes of any malfunctions or inaccuracies in your gasoline gauge in case this crucial piece of equipment stops operating.
You could count your kilometers with each fill-up, but it would be taking a chance. Instead, acquire the skills necessary to correctly identify the issue and resolve it. Let’s quickly review the most prevalent causes:
A defective fuel level transmitting unit is the most frequent cause of a fuel gauge not functioning properly or being incorrect. Inadequate wiring between the gauge and gasoline sender or a blown fuse for the fuel gauge are other potential causes. It’s also possible for the fuel gauge to become damaged.
Your gas gauge will inform you of how much petrol is left in the tank and when it’s time to replenish. You might run out of gas suddenly if your gas gauge isn’t functioning because of the erroneous information it offers.
Running out of petrol has various long-term effects on your car, including increased fuel pump wear and fuel pump overheating, even though it may seem like a relatively small nuisance. Low gasoline levels can also cause the fuel pump to gather up sediments, which block the high-pressure fuel pump, fuel injectors, and fuel filter.
If you experience the fuel gauge not working in your car, it’s critical to locate the problem and then create a repair strategy. Continue reading to discover the most typical reasons for damaged fuel gauges and how to spot them.
A Fuel Gauge: What Is It and How Does It Work?
Visualizing a toilet float valve is the most effective approach to describing the workings of a gas gauge. The tank of your toilet has a float arm.
Your toilet detects when to turn off the water valve after flushing and when the tank has refilled thanks to this floating arm. When a toilet is flushed, water rushes from the tank into the bowl, lowering the float arm along with it.
The water valve on the toilet is currently open, allowing water to flow back into the tank. The valve closes and the water stops flowing when the float arm reaches a specific height.
Similar (albeit more intricate) principles govern how your fuel gauge operates. Additionally, there is a device that resembles a float within your gas tank that is linked to a rheostat (or resistance-sweep; picture the volume control on the radio) that interacts with the fuel gauge directly.
The gauge reads “full” after a fill-up because the electrical resistance at the sender changes when your fuel level is full and transmits the signal to the gauge.
The fuel gauge adjusts to represent the amount of gas in the tank based on the electrical resistance. There may be a problem with the fuel gauge, the sender, or the wiring in between if the fuel gauge consistently displays the readings empty, full, or any other random, nonsensical reading.
Gasoline Fuel Gauge Full Empty Black White
The steps in the following guide you through where to start when troubleshooting fuel gauge difficulties, because there may be several sources of the issue.
Where Is the Fuel Gauge Sender Located In a Car?
A fuel gauge sender is located within your car’s fuel tank. A direct connection will be made to the fuel pump.
The sender has a base with a float as well as a rod attached to it, making it easy to find. This float is hollow in construction and is not heavy. It doesn’t sink since it’s designed to rest on the fuel surface. A rheostat meter on the rod that connects directly to the base measures the amount of fuel in your car’s tank.
Why Do You Experience the Fuel Gauge Not Working Properly Issues In Your Car?
An incorrect fuel gauge is always the result of one of the three components that are required to tell the driver how much gasoline is left in the tank.
1. A Faulty Sending Unit
The transmitting unit is where the process starts in its entirety. The transmitting unit continuously checks the gasoline level in the tank when your car is moving. However, due to its frequent usage, it is vulnerable to wear.
The circuits can continue to function if the contacts become worn. Depending on how the automobile is configured, the fuel gauge may interpret the voltage feedback as indicating that the tank is either empty or full. In this situation, regardless of the amount of fuel in the tank, the gas gauge won’t move.
2. The Circuit Problems
Electricity is used to power the gasoline gauge, hence functional wiring and electronics are necessary. There might not be enough electricity for the gauge to read accurately if the system malfunctions. In certain instances, a broken ground connection is the cause of the problem.
However, any corroded or loose connection might cause problems. Due to the connection to the fuel pump module’s constant exposure to the outside, these flaws are most frequently seen there.
3. A Malfunctioning Fuel Gauge Fuse
The gasoline gauge makes use of both electrical connections and a fuse. The fuse can be found in the box on the driver’s side of your car or under the steering column. Under the hood of certain cars is a fuse box as well.
It takes just a few minutes and is easy to check the fuse. To figure out which fuse controls the gas gauge, see the owner’s handbook.
Benchtop Speedometer and fuel gauge the odometer on a car
When the fuel gauge is merged into the instrument cluster, many contemporary automobiles do not have a separate fuse, although it may be worthwhile to check.
4. A Faulty Fuel Gauge
Even though it’s less likely, this flaw might still be to blame. The gasoline gauge has an internal circuit that is susceptible to failure. The needle might read at any level if this occurs.
It may be a faulty circuit in one location if the gauge is between midway and full or empty. Otherwise, the circuit gets shorted if the needle is fixed at full or empty. The gauge won’t probably ever move again until it is changed.
Unfortunately, in contemporary automobiles, the fuel gauge is frequently merged with the instrument panel.
5. A Broken Instrument Cluster
The instrument cluster is a single, integrated piece of equipment in contemporary vehicles. It’s completely connected, not utilizing several circuits.
The fuel gauge may malfunction in this system if the instrument cluster does. Regrettably, fixing this is one of the most expensive problems.
What are the Symptoms of a Bad Fuel Gauge Sending Unit?
The data may not be transferred accurately if your automobile has a defective fuel gauge sender.
Unpredictable behavior and a fuel gauge that reads empty or excessively full are the main signs of a malfunctioning fuel gauge. Any time the gasoline gauge is performing strangely, a malfunctioning transmitting unit might be to blame.
We examine each of these signs of a malfunctioning fuel-sending machine.
1. Abnormal Fuel Gauge Behavior
Never allow the gasoline gauge to fluctuate rapidly or act abruptly. Until you fill-up the tank, the fuel indicator should continuously go toward empty if everything is working as it should.
However, you can see unusual behavior when the fuel gauge sender begins to fail. The gauge could abruptly change its position or give you an incorrect reading.
You could see the tank is halfway full one moment, and then it might read empty the next. Although the instrument cluster might have an electrical issue, a defective fuel gauge sender is typically to blame.
2. The Fuel Gauge is Stuck at Empty
Additionally, the gasoline tank may appear to be empty when it is not. The transmitting unit has failed if gasoline has been added to the tank but the gauge remains stationary.
The gauge malfunctions when the float snaps or separates from the arm. It depicts an empty tank with nothing visible to read. This problem can also be brought on by a bad resistor in the system.
3. The Fuel Gauge Is Stuck at Full
Although less frequently, the gauge might display fully when the transmitter is malfunctioning. Instead, a defective resistor is frequently the cause of a fuel gauge that is locked at full.
Gas Pump at a Station to Refuel a car that runs on gasoline
The instrument panel receives the incorrect signal from the resistor, which causes it to indicate that the tank is full. The transmitter, though, can be at fault if the resistor isn’t the problem.
How Do You Fix the Fuel Gauge Not Working Problem?
You know there’s a problem if you just filled up and your gasoline gauge still reads empty. The tough part is that it could not always be the fuel gauge.
On the other hand, the gauge can read full even after 300 miles of driving. Although it would be lovely, this indicates that something is not right. Before you run out of petrol, let’s determine what the problem is.
There is a gasoline instrument issue if the gauge is always at full, zero, or displays other erroneous and inconsistent readings. Here’s how to focus your search.
1. Choose an Instrument Self-Test Cluster Process
The simplest place to start is by consulting your owner’s handbook to learn how to conduct an instrument cluster self-test. The procedure for this differs depending on the make and model of your automobile.
Go ahead and run the cluster self-test method after you’ve worked out how to enable it. It’s likely impossible to do this treatment on a car older than 1990.
With contemporary vehicles, this usually entails repeatedly pushing the odometer button and turning on and off the headlights; in older vehicles, it usually entails repeatedly turning on and off the ignition.
The cluster self-test procedure should involve a complete sweep of the fuel gauge needle. If it doesn’t, the fuel gauge itself is the problem. To adequately identify the issue, more tests must be carried out even if the fuel gauge needle sweeps as it should.
2. Examine the Fuel Gauge Fuses
Check the fuse for the gauges/instrument panel by removing the fuse box lid. Replace it with a new one if it is blown.
When more than one gauge is behaving strangely, check this first since it’s probably the answer to your fuel gauge issue. The gasoline transmitting unit or the fuel gauge can be checked in the following step if the fuse is functioning properly.
Before examining the fuel gauge and mailing the unit, take a close look at your car. The gasoline sending unit is located in the trunk behind a panel held in place by merely four screws, however, the fuel gauge on the fifth-generation Honda Civic is difficult to access.
On the other hand, a third-generation Chevy Camaro’s gasoline sending unit may be reached without removing the gas tank, while the fuel gauge is simple to reach after removing eight screws. Whatever is easiest on your car should be used first.
3. Test or Visually Inspect the Sending Unit of the Fuel Gauge
The gasoline-sending unit/fuel pump component should typically be removed from the tank for inspection once your wiring and fuse tests have been successful. Sometimes the wire going up and out of the transmitting unit will be destroyed, along with the arm or float.
Resistance on earlier automobiles with a 1-wire transmitting unit may be simply evaluated. The resistance will read 0 ohms when the tank is empty and 30, or 60, respectively, ohms when it is full in the majority of older sending units.
Put your multimeter on the resistance (ohms) setting, then touch one probe to the transmitting terminal and the other to the ground to test this. You should see a change in the resistance on the multimeter as you slowly raise and lower the float. If the resistance does not change, the transmitting unit is malfunctioning.
This is more challenging, if not impossible, to execute on newer sending units that have the gasoline pump built into the assembly, but frequently test techniques may be obtained online. On a recent car, the complete fuel pump system must, sadly, be replaced if the sending unit is suspicious.
4. Use a Multimeter to Test the Fuel Gauge
Typically, the gasoline gauge on older cars or boats has two terminals. When the ignition is turned on, 12V power is applied to one of these connections. The transmitting wire from the sending unit is connected to the opposite terminal.
Next, the gauge is grounded. If the power line does not have 12V, you will need to troubleshoot the power issue. Additionally, you may check the continuity between the transmitting terminal at the dash and the tank’s connection point.
If there is no continuity, this wire has been broken someplace. Remove the instrument cluster from the dash and use the multimeter to measure resistance to examine the fuel gauge itself.
You may test various gauges in different ways, so look for the right test technique in a service manual or online. The gauge cluster and fuel gauge on more recent automobiles are far more challenging, if not impossible, to test.
On modern vehicles, disconnect the instrument cluster from the dash then disassemble it if necessary to access the fuel gauge alone.
Although gauges themselves can malfunction, most issues are really with the wiring or the transmitting unit, so it’s important to test out all other possibilities before confronting the gauge.
5. Verify the Wiring to the Fuel Gauge
Although it is not very challenging, testing the wiring might take some time. The gas tank itself is the ideal location to begin. The wire harness that controls electricity for the fuel pump, as well as the sending unit, is located at the gas tank on the majority of automobiles.
Older cars without an electric fuel pump often only have one wire for the sending unit, along with a ground wire that is hooked to one of the sending unit’s screws and grounds out at the frame close by. First, you must inspect the ground connections.
It is fairly usual for a transmitting unit ground to fail, even though the wire is still in good condition, because of the splashes of rain, salt, snow, etc. at the back of the car. Clean, then reattach the ground connection after removal.
You must visually check the wiring since any break or damage to the ground or transmitting unit wire will affect the gauge. Most of the time, you’ll need to lower the gas tank to get access to the mounting hole for the gasoline tank sending unit and fuel pump.
Make careful to only do this when the car has either very little petrol left or none at all. The wiring near the tank or the transmitting unit is typically the cause of most gas gauge problems.
How Much Does a Fuel Gauge Repair Cost?
The price will change based on the nature of the problem. A new fuse, which costs $10, or the repair of the fuel gauge sender, which costs up to $800 after work, can fix a problem. The reply is that it depends. Here is a list of the typical replacement components and their prices.
Price of a New Fuel Gauge Sender
Most frequently, the issue is with the sender of the fuel gauge. The majority of the cost of repairing this component is labor-related.
Costs range from $250 and $800, depending on the make and model of your automobile and the particular sender that you choose. If you feel comfortable, you can replace this part yourself and save a lot of money.
Replacement Cost for the Fuel Gauge Fuse
The fuse is another replacement component that can solve your fuel gauge. You can accomplish this yourself quite easily and for a very little cost. Fuse replacement generally costs between $10 and $20, however, certain specialist fuses can go as much as $100.
Replacement Cost for the Fuel Gauge Itself
You’re in luck if the gauge itself is the problem. Depending on the make and model of your automobile, this item should only cost between $50 and $200 to repair.
If you want to have this changed properly, you will need to take the cost of replacement into account. The final price will range from $200 to $400.
How Can I Tell Whether the Fuel Gauge on My Car Is Accurate?
Depending on the distance and style of driving, a working fuel gauge should deplete at a constant rate after a fill-up. If the fuel indicator reads inconsistently or says the tank is full for more than 75 miles, there could be a problem.
Similar to that, it has to be looked at if the gauge becomes empty extremely quickly after the tank has been filled.
There may be a self-test technique for the instrument cluster for vehicles that are 20 years old and newer that verifies that the gauge may go from full to empty. Every car has a unique procedure that is described in the owner’s handbook.
The amount of fuel that your vehicle’s tank can contain in gallons or liters, as well as its fuel efficiency, are both listed in the owner’s handbook. Using those two figures, you may estimate how far you should be able to go on a full tank.
The simplest way to determine your car’s fuel efficiency is to keep note of how many miles you go between fill-ups and divide that figure by the number of gallons of gas you put in at the subsequent fill-up.
Monitoring this will enable you to identify any issues with the vehicle before they become significant ones.
Can a Fuel Gauge Be Calibrated?
By comparing the location of the float to a calibration curve that accounts for the geometry of the tank, modern automakers may utilize a computer within the car to slightly alter the movement of the fuel gauge.
For a more compact design, fuel tanks frequently have an unusual form and cram themselves between other components of the car.
Because the automobile has been designed to recognize that the gasoline level isn’t changing that quickly, moving up and down inclines doesn’t cause the fuel gauge needle to change on the fuel gauge as quickly as gravity moves the float itself.
Although it is conceivable, it is not recommended unless you have a clear cause and precise instructions for your automobile to calibrate a gasoline gauge yourself.
By utilizing a multimeter, resistor, and power supply to calibrate the gauge, you might be able to learn the process from an expert. To prevent harm to the automobile, consult a specialist if you are doubtful.
Finding fuel gauge problems might be difficult. One of those crucial meters, if it malfunctions, may leave you stranded or at the least, force you to continually monitor your mileage out of concern for running out of petrol.
Always start with the fundamentals, such as fuses, wiring, and grounds, before moving on to more complex options. The issues are typically located in the fundamentals.
Driving for a long time with a malfunctioning fuel gauge is not a good idea since it might leave you stranded or cause the fuel pump to gather up too much sediment and overheat.
It’s possible that you can solve this issue on a budget. Knowing how the system works and doing some home troubleshooting can help you find the problem and fix it.
Nyangano Maurice specializes in vehicle troubleshooting and has more than 10 years of experience in the automobile industry. Over many years of experience as a car mechanic, he has acquired a broad range of skills, including engine repair, brake systems, electrical systems, and more. He frequently hosts community workshops and training programs to help motor vehicle owners understand their vehicles better.