Just purchased a 2001 vette from AZ and drove it back to CO. Thrilled to death with the car, and very happy to make my first post here. I ran into a problem I know nothing about and am looking for some help. We bought the car and filled it up with gas immediately, then began our drive home. When the fuel gauge reached 3/8th of a tank, the gauge suddenly dropped to empty, the display read "low fuel" and my "check guages" light came on. I was worried that maybe we had a leak so I pulled into a station and filled up, it wasn't empty. I ran that tank down to the exact same spot, and again at 3/8th of a tank the guage dropped to empty. So my question is, is this a sensor issue or guage issue? If its a sensor issue, where would it be located? To complicate this issue, when we picked up the car the guage read about 1/4 of a tank. So my theory is that if I were to keep driving past 3/8th and down to 1/4 of a tank, the guage would pick back up and read correctly. I hope this wasn't too much rambling. Any help on what this issue is would be much appreciated.

 

Pretty common issue- mine does similarly. Believe it has to do with the level in the tank sticking or something. Some recommend adding Chevron Techron when you fill up a couple of times in a row to loosen things up.

 

Techron should fix it.

 

 

Very common C5 problem and as some have said Techron could help.

 

The sensor in the tank can get gunked up and cause the problem you are seeing. The techron cleans up the sensor and resolves the problem. It may take a tank or two to fully clean up the sensor.

Once you get it fixed that way, I would suggest adding a bottle 1-2x a year to prevent it going forward.

 

Congrats on the car and WELCOME to the FORUM!

Like others have stated, it common and caused by sulfur deposits on the sensor wiper arm. You do know you have Two fuel tanks and two fuel sensors,,, CORRECT?

Your car has the ability to display and clear all the DTCs that indicate an issue. If you dont know how to read and clear your own DTCs, here is a detailed write up for you:

READING YOUR Engine and Body Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!



If you read the PCM DTC it will detail what fuel level sensor is at fault. A few treatments of Chevron Techron "SHOULD" remove the deposits causing your issue. Once you clear the DTCs for the fuel system, you should be able to restore gage operation until it errors out again.

Always read and post any DTCs that you have when you make a request for help. Without the DTCs it is a CRAP SHOOT on whats wrong and how to fix it.

Bill C

 

I had the exact same problem, and with the help of a few fellow forum members, I purchased the Techron Cleaner, but before I added it, I cleared the codes, and wouldnt you know, it fixed itself, I then added the Techron for good measure. Thanks to those members who assisted.
Steve

 

I had this problem with my 2000 vette after purchasing a aftermarket warranty do this it really helps i took the car over to my chevrolet dealer and they replaced both sending units for sludge buildup on and around the sending unit arm and float this causing bad and incorrect readings.and yes Techron fuel additive or a lucas fuel treatment also work to keep these parts clean. Happy speeding

 

Bill, this is THE most useful post I've seen on the board yet! If it's not a sticky, the mods should make it one!

 

There are SOOOOOOOOOOOOO many new forum members and first time Corvette owners that my fingers were numb writing about DTCs codes and how to read them. So, I made a word document, saved it to my desk top and when I need it, its easy to pull up.

Comes in handy and saves a bunch of typing.

Anyone is welcome to it, copy it and spread the word.

Bill

 

Welcome to the Forum and congrats on the new ride. It is customary to fill out your profile completely, folks feel more comfortable communicating with you...enjoy the ride.

 

I agree

 

Sorry about that, updated it just now. Picked up 2 bottles of techron today, hopefully that will clear things up. Great information, I really appreciate it.