Skip the auto shop - Our mechanics make house calls

Q: After fill-up, gauge went to top, then dropped to middle and stuck there

asked by on

The last time I filled up my Mazda, the gauge went all the way to top about 15 minutes after fill-up and then after driving about an hour, it dropped to middle and stuck there. How do I fix this?

A: The fuel sending unit inside the fuel tank ...

The fuel sending unit inside the fuel tank uses a variable resistor unit to control the fuel gauge. If the sending unit is faulty then it could fail in any position, causing the gauge to not work correctly. A true test is to remove the sender and check the resistance of the sender while moving the float up and down. If it does not match the specification, then it should be replaced.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I have a coolant leak in the hose just under the manifold on my 2007 Mazda CX7

If you can see the coolant line that is damaged, and can reach both ends of the hose, you should be able to replace the coolant line rather easily after removing the engine cover and air cleaner. However, on your...

Q: The car won't start after the gas is put in

Hello. Most of the time, if your car suddenly will crank and not start after fueling, it is because of a failed fuel pump. The fuel pump in the fuel tank is kept cool with the fuel in the tank....

Q: Power window not functioning properly

This is a common issue in cars. There can be several things wrong. The most common issues are window switches or faulty motors when its just one particular window that is not working. But electrical circuit problems can also occur....

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...