I have a small problem I'm hoping someone here has had experience with before. I did some work for a customer a few days ago where we tuned his 2015 Denali. Now he is complaining of a fuel gauge that moves excessively under braking and acceleration. He says that if the fuel level is at or below 1/4 tank, it will move enough that it turns on the low fuel light. I have never had anyone complain about this issue before, and I don't know where to start on trying to fix the problem. I have verified that the calibration ID for the fuel system matches what the GM TIS website says it should be, and EFILive doesn't give any access to the fuel gauge calibration tables. I really have no idea where to go from here or what to tell the guy, but I'm taking a long shot hoping someone else has experienced this issue and has a fix. For the record, we did not touch his fuel tank or anything related to it either.
