I had my Yukon tuned by mean05 back in 2008. Recently started getting Reduced Engine Power on a frequent basis. I've done research and found it could need a tune update. mean05 will not respond to vm, text or pm's. So my question is: is it possible to have someone else work the tune? If so, who in the Mesquite, TX (or Dallas) area does reliable work?

 

It will not just throw a code because it needs to be updated. There is a problem somewhere. What codes is it throwning when it goes into REP?

 

^ what this guy said

 

These darned drive by wire trucks have been known to have the throttle bodies go bad, the throttle position sensors in them can take a crap and then it will want to go into REP mode.

Had one go bad on my 03 this summer, had a p2135 code and anything over 10% throttle and truck would go into REP. The p2135 I had when mine went bad if I remember just off the top of my head said something to the effect of tps correlation issues between sensors A and B.

 

GM also has a TSB about the wiring becoming brittle and breaking.

Without the trouble code's we don't know where to point you.

 

Yes they did, good point bringing that up I forgot about that. The part of the wiring harness that goes to the throttle body. Their is a good set of test procedures I found online before that are right from the GM service bulletin that explain what wires to check out and whether or not it's a wiring issue or the throttle body itself. I think their have even been some cases where the TAC (throttle actuator control) module on the firewall has been bad as well.

 

Had problems with mine most of the summer, finally fixed it be replacing wiring all the way back to the tac module.