Don’t know how much gas in my car!

Hi! 1st post here. I could really use a little wisdom here. I had my fuel pump replaced at Christmas time last year. A couple of months later I was parked at sonic and I watched my gas gauge needle fall slowly until it said my car had no gas. I turned the car off and turned it back on and the needle went to about 3/4 full tank. After idling a couple more minutes the needle dropped back down to empty. So I had my fuel pump replaced for the second time. This is the driver side fuel pump. He also replaced the sensor but hit it has not fixed my gas tank indicator problem. I took it to another shop this morning and they told me that since my digital gas indicator is also incorrect that it may be an instrumentation problem and I may have to take it to the dealer. I’m terrified it’s gonna cost a ton. Does anybody know anything about this? I was hoping it would just be a sensor.

There are two fuel level sensors, one on each side of the fuel tank. A professional diagnostic scan tool can rear each sensor value and check for open circuit faults.

Without a scan tool, an amateur mechanic can measure the resistance of the level units accessed under the back seat.

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Thanks so much! I appreciate your reply. The mechanic I took it to today suggested I take it to the dealership:(((. Guess that’s my best bet as it could be an instrumentation problem, so I’ve been told. Thank you for your help!

Chain auto shops (I go to Auto Zone because it’s convenient) will lend you a scan tool free. I think you’re better off if you have a diagnosis before you go to the shop.

The basic scan tools they lend you or which the employee uses won’t be able to retrieve this type of data.

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Didn’t know this. I can’t scan my '87 Toyota pickup. Thanks.

Thank you for this! Right now my car’s check engine light is miraculously not on since being on for about five years for random things. So yeah I’m not sure the code is going to show up for my gas tank since you’re not working. It seems like it would but like I said there’s no lie. I’m taking it Advance auto parts first thing in the morning to see if it will scan for anything before taking it to the dealership. Great advice. Thank you!

Omg I hate autocorrect. Sorry
about that. *since IT’S not working.

This symptom could result if there’s any corrosion or poor electrical connection at the wiring harness/fuel level sensor variable resistor connector. Make sure your shop tech takes a close look at those pins and sockets with a bright flashlight before presuming the problem lays elsewhere

Omgoodness I never even thought of that! I mean I live in a pretty humid climate and poor baby is not garage-kept, AND she’s got 160,000 miles. So I would not be surprised if there’s some corrosion there. Thanks ao much for the advice!