Ok, we bought a 2008 tahoe hybrid 4x4 in Jan. 2009. As of 5 weeks ago, my wife has had complaints of the vehicle not taking off from a stop when she presses the accelerator. She said that she pushes it and nothing happens, then she would let off of it, when she applied the accelerator again, the vehicle would take off and stutter a little. We just got the vehicle back from the dealer which told us that this is normal operation for a hybrid as the vehicle is working as designed. Today I experienced this issue in where I pressed the accelerator and it would start to take off and hesitate then it would move. I noticed that the RPM's were at 2000 and we weren't even at 10 mph yet. I stopped again and when I pressed the accelerator again the rpm's jumped to 2000 immediately and we began to move. It didn't seem like a slipping clutch pack or anything that you would assume in a run of the mill automatic. I plan on calling the service manager tomorrow to talk to him, but would like some more information from others that may have dealt with an issue like this in the past. I also have a bone to pick with them anyway as the leather is cracking on the drivers and passengers seat. Any help would be greatly appreciated.

Thanks

 

2008? maybe the same wiring harness issue I had with a bad crip in a subcontracted part? mine actually just shut down but it could be a similar issue. this was found in some 2008's. mine was replaced with no further issues. FWIW mine starts out a 0 rpms up to 30 mph depending on traffic flow. sometimes I can drive the 4 miles from my office to home on elec only depending on the volume of traffic

 

What was your vehicle's build date? I can usually get the tahoe to take off in electric mode only but lately it has been close to 100 deg. F hear in Cincy with heat index of 105+ and it seems like the tahoe won't take off or stay in battery as long with the A/C running. Here is something else that is interesting, I can unplug the battery and reset the EMU, and my wife (non hybrid friendly driver) can get 18 mpg to 19 mpg avg. After about 2 fill up's, she gets about 15 to 16 mpg avg. I know something is wrong, but don't know how to prove it to the dealer.

 

Well, we can all tell you that the quote from the dealer:
"this is normal operation for a hybrid as the vehicle is working as designed" is wrong.
The hybrid drives just like a regular vehicle. Yes, you will notice some slight noises (police sounds) some little drivetrain sounds (not really vibrations, but some new sounds) as the modes change, but the vehicle drives like every other car on the road if you just get in and drive.
If it does not move when you press the accelerator pedal, it is broken. That is not normal and is very, very likely due to the harness, as this behavior does seem quite similar to the recalled behavior.
Also, I would find another dealer that has better trained technicians, after they fix your leather. My 2008 seats are perfect (black leather in SoCal and it is kept outside) with 45K miles on it.

 

[quote=wsumsd98;226017]What was your vehicle's build date? )
mine was a jan 08 build. I agree with fjungman ,,, this is a totally normal vehicle. if you didnt know it was a hybrid you would think its a total run of the mill yukon tahoe. find a better dealer and I have averaged 19.7 mpg 0ver the last 10 tanks of gas 80% city driving.you really have to relearn your driving techniques as your right foot controls a lot of technology!

 

Fjungman, what wire harness was replaced on your yukon? What were the symptoms of your vehicle that mandated that wire harness be changed?

Thanks

 

Hi There,

I just wanted to post that I am experiencing the same thing. I own a 2008 GMC Hybrid Yukon acts the same way. Interestingly enough, I only seem to experience it during the summer months when the temperature is very hot. I live in AZ so during the summer it happens on and off for a few months. I just got it back from the dealer last week where they replaced the Aux Transmission pump but it acted up the very next day. I need to look into the harness issue again, but I thought it was already replaced last year. I also saw that Kipper777 has a similar complaint under the heading "Transmission Issues - 2WD Tahoe??".

If anyone else has some insight, it would be greatly appreciated. The symptom is very intermittent and I can never get it to reproduce so the Dealers (I've tried two) are having difficulty diagnosing the problem.

Thanks for the help.

 

wsumsd98, you meant to direct your question at Jet1.

 

Fjungman, my apologies! Jet1 When you had the wire harness replaced on your Yukon, what were the symptoms and what is the actual name of the wire harness that was replaced on your Yukon?

 

wsumsd98

I had to have my wiring harness replaced like Jet1. My symptoms were, that after some short runs, the truck refused to start. I would wait for a while, and then it would start and i would have engine check light and a few other things on. On my most scary occasion, after getting her moving again I took the truck out on the motorway, and while doing about 60mph, everything stopped! The engine, the power steering, and the power assist to the brakes. I managed to get it safely to the hard shoulder, and then waited. About five minutes later, I started it up, and very slowly took it home, only to have a recovery vehicle take it to the dealer the next day. I wasn't going to drive it in traffic after that scary moment.
The dealer managed to diagnose the problem with their Tech2 computer when it happened to them in the workshop.
Having said all that, I have the part numbers for the wire harness replacement and the associated parts. If i remember rightly there are gaskets that are needed, because they have to take off some ancillary systems to get to the harness.
I also have some schematic drawings to go with it. Drop me a line if you would like them.