Fuel tank indicator shows Full when the tank is probably empty: 2001 Honda Civic

Current symptom:

My 2001 Honda Civic fuel tank indicator is showing FULL when the tank is probably 1/2 EMPTY (100+ miles driven after last refuel). The indicator has not moved (when ignition is on) since I last refueled the tank. (When ignition is off, the indicator lowers to “empty” as expected).

I am scared that the fuel indicator has gone faulty. Is it? how much would it cost to fix?

Additional info:

Two weeks ago I took my 2001 Honda Civic to the dealership for 40,000 mi maintenance. The fuel tank indicator was fine. On the report, they suggested I changed the tires, alignments, transmission liquid flush, power steering fluid flush, and fuel injection fluid flush. Upon talking to several other auto mechanics, I decided to only do the tire / alignment changes for now.

About a week after replacing the tires, the fuel tank indicator shows almost empty so I refueled (the indicator rised to “full” as expected.)

Usually a full tank gives me about 330 miles before the warning light flashes, and filling up takes about 10 Gallons. An interesting thing this time was that the tank indicator was not even at the red warning level, but 11.5 Gallon went into the tank before the tank was full. i thought it was just that the gas station was cheating and didn’t pay attention to it.

I have driven the car about 100 miles since that, but the fuel indicator is still showing full.

one additional info:

during the 40k scheduled maintenance, I also let the dealer to replace a broken lower control arm bushing. (a $380 job! I feel the dealer is probably ripping me off… that’s why i decided against their other suggestions)

A fuel gauge that is showing FULL all the time usually means either the fuel tank sending unit is defective, the gauge is defective, or a wire between the gauge and sender is bared and making contact with ground. It’s usually the first item and I cannot give you a price; there is too much variation on labor rates and parts sources.

I see no way that anyone could have done anything to cause this. The car is 8 years old and things happen.
From your posts, it appears that you do not want to spend money with maintenance services and think that everyone is ripping you off, from the dealer to the gas station.
Not so.
I could not see a power steering flush but with the vehicle age a trans flush or fuel injection cleaning could be in order. That’s hard for me to say.

I have no idea if you needed a control arm bushing or not but those things can get pricy. Since you have had to replace tires, control arm bushing (complete arm I assume), and have an alignment I can only assume your car has been wrecked or damaged in some way to cause a control arm problem. Pothole, railroad tracks, ditch, or whatever.
You did not state what problems you were having with tire wear or vehicle handling.

The fact that you do not like the price does not mean that you were ripped off.

It sounds like you have learned that dealers are there to buy cars from and have them do work that is covered under the warranty and seldom anything else.

It appears to me that the tank gauge, wire or sender (my money would be on the sender unit) and I would be very surprised if there was any connection with any of the work done. It is just one of those things.

Congratulations on figuring out ADP ( Additional Dealer Profit ) :slight_smile: