Why is my gas gauge reading incorrectly?

January 17th, 2022 by

Most drivers pay pretty close attention to their car’s gas gauge. After all, it’s important to know when it’s time to gas up so you don’t find yourself stuck on the side of the road with an empty fuel tank. However, what happens when your car’s gas gauge just… stops working? Remember, it’s a part, and just like any other part, it can malfunction or wear out. Toyota of Orlando’s service techs are here to help you figure out why your gas gauge isn’t working and what to do about it.

Orlando Toyota service

Before we can fully explain what’s going on with your Orlando Toyota, we need to break down the pieces and parts involved:

  • The most common reason for the fuel gauge to malfunction in a car is due to a bad fuel sending unit.
  • The fuel sending unit measures the amount of gas in the tank and communicates the level to the fuel gauge in your car’s dashboard.
  • The fuel sending unit is composed of a float, a metal rod or arm, and a variable resistor.
    • The float floats on top of the fuel in the tank.
    • The float is connected to the variable resistor by the metal rod.
    • The variable resistor connects to the gas gauge to communicate how much fuel is in the tank.

The three main issue with gas gauges

Now, let’s talk about the issues at hand and what to do about them.

Issue #1: The gauge is stuck on full. You filled up a week ago and you’ve been driving regularly. You know you’re using full, but the gas gauge still reads completely full. No, you haven’t been blessed with suddenly magically enhanced fuel efficiency – it’s a lot more likely that you’re having an issue with your variable resistor. It could be faulty wiring, an open circuit issue in the resistor, or rarely, just a bad gauge. Whatever it is, it’s not a DIY fix and it’s worth having our techs

Issue #2: The gauge is stuck on empty. Conversely, you KNOW you filled up your tank (and so does your bank account). So why is your car still telling you that the tank is empty? This issue is usually caused by one of a few issues – either the float has separated from the metal arm and isn’t sending any information about fuel level, the variable resistor is faulty and malfunctioning, or the wires in the system have corroded and are no longer sending information.

Issue #3: The gauge swings back and forth between full and empty with no rhyme or reason. Does it feel like you’re always playing a guessing game when trying to figure out how much fuel is in the tank? This is usually a result of the float “sticking” in place and then being jolted back into motion by the movement of the car. It can cause irregular readings. Another cause could be a faulty gauge itself.

Whatever the issue and reason for it. this is definite;y one for the experts! Call Toyota of Orlando’s service center today for an appointment and let our techs check things out. We’re open seven days a week at (407) 298-0001 and we’re conveniently located just off I-4 near the Millenia Mall at 3575 Vineland Road.

Posted in Toyota Service