Hi everyone, I just purchased a 2008 yukon hybrid which I am very excited about, but I am worried about something going wrong with it. I don't have any experience with hybrid cars and don't know what to look for. Yesterday the ck engine light came on I read that it could be the gas cap and I had just put gas in the car the night before, so I tightened the cap and the light turned off after a few starts. I just connected my on star today and they ran a dignostic and said it had a problem with the propulsion system. Please help!

 

That vehicle is the first year of a large step forward in complex technology. Writing down the exact code # is very important.


Any time that light comes on, several computers on-board log and store code information.


The big-box Auto Supply stores can read codes for you but they are limited in the depth of information.


A dealer that will actually take the time can pull Freeze Frames. These are much more in-depth logs of what the vehicle was doing when the code set.


You are driving a computer network.

 

I spoke with on star again and they gave me the code of P0AC4.

 

All that means is that the Hybrid computer told the Engine computer to turn on the Check Engine Light. They should be able to go deeper than that.


The codes of value are in the Hybrid computer.

 

Best advice for a "Check Engine Light" is to take it to the Dealer.


It may or may not have anything to do with the Hybrid System.


For Example one of my CEL warnings was a bad spark plug.