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Erractic Fuel Guage Reading


Below is a service bulletin from GM addressing a problem many of us have had--erratic fuel gage reading. If you go by the bulletin, this reprogramming has to be accomplished at a GM dealership, but I also want to give you some tried and proven hints that I have used or learned about from others.

The root cause of this problem has been found to be high-sulphur fuels playing havoc with the electronic sending units. Some people have switched to different kinds of fuels (namely Chevron), and found this fuel to eliminate the problem. Others have used Chevron Techron fuel additive and found that works well. I had this problem and I used a potent fuel additive called BG-44 and my fuel quantity indicator returned to normal operation. The most extensive and costly repair for this problem is replacing the fuel tank sending units, but I would suggest trying a different fuel or a fuel additive before a reprogramming or replacement of the sending unit.

1999-2002: Service Bulletin: Erratic Fuel Gauge Reading

(Reprogram the PCM)

Subject: Erratic Fuel Gauge Reading (Reprogram the PCM)

Source: Chevrolet Dealer Technical Service Bulletin

Number: 02-06-04-010A - (06/27-2003)

Models: 1999-2002 Chevrolet Corvette

This bulletin is being revised to add models and update the Correction and Warranty Information.


Some owners may comment about the fuel gauge intermittently indicating an empty reading and then return to the correct fuel level indication.


This condition may result when fuel blends containing aggressive sulphur compounds react with the fuel sending assembly, which may result in voltage spikes being induced on the fuel level signal to the PCM. Use of another fuel blend may reverse this reaction and return the system to normal operation.


Reprogram the PCM with the new service calibration which is (was) available in the June 2003, Techline TIS release sent to the dealers on 6/28/03 . Use this version 7 or later data update.