Ok, I think its funny that we all say this in the beginning of most threads now but... I searched for this (in problem and service and in recalls) and only really found the gas gauges not going all the way to full but this is different, so if it is out there dont flame me, just point me in the right direction and i will be on my way....

This weekend I filled my car up about half tank. I drove back home, about 20 miles. I got back in the car and noticed that the gas has moved up. I was like, well that could happen. So drove and drove and it was still going up. Now I was thinking either there is a gas fairy following me, which would be ****, or somehting is wrong..

So I went all the way till I had a "full" and filled up... Would you guess it went to empty.. lol
The gauge is reading completely backwards...

So anybody heard of this, if so whats the fix? Dealer says since I have had a tune, they will not look into it unless they get a diagnostic fee...

 

mine does that, only my empty is at about half way on the gauge and my full is at the empty mark,. it is due to GM changine the way the sending unit in the gas tank was put in. they changed in in 06 an 07 so if you have an 06 or 07 then thats easily why. i heard it was easily fixable in hptuners tho. i just need to send my pcm back to zzp an they will reflash it but i don't feel like waiting for my pcm to get back so i just deal with it for now.

 

Well if this is true, someone that knows about this in HPtuners, can you help?

 

i heard that from a dyno tuner at a shop somewhere. if you have a reliable dyno tuning shop around ask them or call zzp and ask what they did to fix it, i'm sure if you talk to tech support at zzp they might be able to help ya

 

Bump

 

Did you have the tune recently reflashed?

 

I just got Dyno Tuned.

 

If it happened almost right after getting tuned, someone probably threw the wrong operating system onto your PCM. Sounds like you got an 05-06 OS on an 07 or an 07 OS onto an 05-06.