I have a 2008 GMC Yukon hybrid with about 126,000 miles. It recently died while traveling on the highway. Several error messages were shown: Service Hybrid System, Reduced Power, Service Stabilitrak, etc. It has been in the dealership for more than 60 days. They are currently replacing their 3rd module. So far nothing has worked. All of the electrical system was powering up: radio, guages, lights etc. But it would not crank. The dealership mentioned that there was no communication in the bus that controls the start. the hybrid battery is fine. Any ideas?

 

There are numerous information bulletins in the Serial DataCommunications Busses.
Here is just one of them. http://www.autocodes.com/uploads/gmc/08-07-30-021E.pdf
If we can find this with a Google search…? What is their problem?This is real important.
Without PERFECT serial data communication between all themajor modules, you won’t go.

 

That bulletin is not the only one out there and available to the dealers.


This whole thing is most likely a wire that rubbed and is touching ground somewhere.

 

Other places to look


http://gm.oemdtc.com/6639/hybrid-no-...let-gmc-hybrid


They can replace all the "modules" , if a wire is bad it won't matter.


When I was a Mr. GoodWrench mechanic, I called this the Easter Egg Hunt/Fix method
Keep changing parts until the problem or the customer goes away.