ODB2 Problem on 2007 Chevy Malibu LT

[George Tsigaridis]

Hello everyone,
I am writing on this forum to get some help on trouble shooting a strange problem.
My car (2007 Chevy Malibu LT) has an engine light on but almost all scanners will tell me that they can not communicate, even with my new/used snap-on verus pro (all I could get was to see the factory radio and ABS and airbag everything but the ECU and the transmission). Only have a very cheap scanner that I got a couple of years ago on a black Friday that will talk to the car and tells me it’s a evap code (which doesn’t make cents as the car runs and drives smoothly). The main problem is why it will not let the other scanners (I have tried a number of different scanners and the car will start misfiring or start playing with the gauges). Also when my car is under half tank it show the fuel gauge at the right area, but when you will it up it drops to empty until the the gas drops to under half a tank again. I have seen the gauge move up to full when your driving and hits a bump. I think it maybe a loss ground going to the BCM or ECU. I tried a couple of weeks ago to see if I could find the problem wire (if it is a wire) when I parked at home the fuel gauge showed full tank and when I moved the wires it went to empty but it I couldn’t make it go back to full tank again and it was very very cold so didn’t want to do more damage from the cold weather.
This is not my main car and don’t use it that much but work out of town so I don’t have to much time to just try everything I can think of (yes I am a DIYer that loves working on anything that I can get dirty with LOL). I would like to get some ideas what to look for and what to try that may point me in the correct direction. And sorry if I am not naming them correctly the control modules, still learning.
About me: I install/service/trouble shoot video surveillance systems on transit/school buses. I get called in when others can’t find why the camera system is not working correctly or some installer has made a mess of everything and I am their to save the day LOL.
Thanks

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