My guess would be that it has to do with the way this vehicle's charging system is different compared to a normal vehicle. Unlike a traditional vehicle with an alternator, this vehicle does not have one. Instead the power and charging is generated from the Hybrid battery and Hybrid system. The computer monitors the voltage and decides when to charge the accessory battery (12V) and most likely when you measured it the system was not in charging mode and the battery had a draw on it. It is not really possible to measure the charging system on a Hybrid without a Tech II because it does not have the constant flow like a traditional alternator.

The Stabilitrak message is a bit strange??? Not sure what to tell you on that one.

 

Wow. I did not realize that. It is starting to makes sense to me. The GM Hybrids are designed to run up to 4 miles @ 25mph on battery right? Usually, when I enter my subdivision, my house is so close to the entrance that my vehicle stays in battery mode all the way inside my garage. The distance is probably not great enough to discharge both the 300v and 12v batteries but with the air, radio and the hybrid motors all drawing power and the engine not running, a voltage drop has to occur.

The voltage readings I take directly from the battery is the same as the DIC except that the DIC rounds it up and mine gets to tenth of a volt. I guess the voltage drop was not enough for the run down protection to kick in.

 

Today GM called after they got a notice from the BBB. They told me instead of the 5000 miles of usage in the first offer, they are now going by Lemon Law rules which means I now have to pay the full mileage. So offer has gone worse. Also they are declining my repurchase request. (LIKE I CARE, at this point)

 

WOW. That is unfortunate, sorry to hear they are taking that stance. I would go through the arbitration process and have all your facts ready. Go to the arbitration with every piece of documentation you have in a organized manner. Do not bring any subjective info like posts form a forum or a blog as it will not help and might hurt you. Do NOT show any emotion at the hearing and stick to the facts. They will try to prove that the vehicle is fixed and that there is no recurring problem. If any issues arise between now and the hearing go right to the dealer and have them write a new repair order. If they will not then call GM customer asisstance and document the situation and get a case number for your file to back up that you attempted to take it in to the service department. Also, keep a camera in the vehicle and snap a shot of any messages that appear. Make sure the date and time are stamped on the photo. Obviously if you experience ANY brake problems do not drive the vehicle, call Roadside Assistance immediately and have it towed. Also, be sure to bring copies of the offer letter from GM as well as documentation on the conversation yesterday.

Good luck and feel free to PM me if you want to speak directly and privately. It sounds like you have done what you have to do so far and I applaud your ability to keep a level head. Keep your cool and document everything.

 

I own a 2008 Tahoe Hybrid and just came home to the airport from a business trip. The truck was completely dead. After a jump start (following the manual’s instructions), I let the truck run for a bit in place and then as I put it in gear, I too got the Stabilitrack, Brakes, ABS, and check engine lights all illuminated. I was traveling at less than 5 mph, but went to brake to pull into a parking spot. No brakes, no vacuum assist, no nothing. I sat in the spot wondering what to do next. I let the truck run for a bit, turned it off, waited, then re-started it (it had enough juice to restart at this point) and all lights were now off, but the check engine light was on. Pushed OnStar and they indicated while it may be OK to drive as long as I had braking, that they were showing Stabilitrack, ABS, and a general fault code and to get to a dealer as soon as convenient. I took the truck in yesterday morning and after 8 hours on the phone with GM Engineering, they do not know what is wrong. They have a video conference with GM techs on Monday where they will hook up the truck to the dealership service systems and be able to transmit data to GM Engineering. Not good and I am not sure if I feel safe, now knowing that brakes could fail at any time…I will keep everyone posted…

 

I am not sure why they are all having so much trouble with this? Based on their own bulletin of how if the battery is disconnected improperly these exact symptoms may occur and the fact that your battery was dead and had to be jumped would make me believe that their is some sort of communication error between modules due to a low or no voltage situation. It seems that in each time after the second restart with the battery not being dead any longer that the system is realizing communication is back up and vital functions are again working as designed. Now, hopefully all of these complaints will eventually lead to some sort of software update to prevent this from happening when a battery goes dead. There seems to be a common trend though, dead battery followed by these series of events.

Let us know what happens. I suspect that you will eventually get the truck back with an explanation that it was all related to the dead battery event and that they just wanted to be sure before they gave it back to you.

 

Yup, it's a common problem with a simple solution. I reported about it months ago when I first got my Tahoe. The battery wears down easily in these rigs so you can't leave the key off and the accesories on for long. Early on when this happened to me I had the same warning lights and no power brakes. You'll also find the engine misfires and surges. I (carefully) drove around for about 10 miles, went home and parked it, then started it up in the morning and everything was fine. The second time it happened, it was after my wife merely turned the car off but left the keys in the ignotion and came inside the house for a couple hours. I eventually replaced the battery at the dealership. That was at 800 miles and now I have over 20,000 without any further issues. Just because it comes with a weak battery does not make the vehicle a lemon. People need to calm down, get a more powerful battery at their dealer (with reprogram), and everything will be fine. Then just keep the engine on whenever stopped and listening to the radio or with the headlights on (especially in auto stop since here the hybrid batteries take over) and don't leave the keys in the ignition for long periods of time and you'll be fine.

 

I understand it now, but why after just having a truck sit for 10 days with nothing running on it (parked in an enclosed parking structure), would the accesory battery go from what I believe was fully charged to fully dead? Is that normal? All my other cars have at certain points sat for up to 3-4 weeks without any issues. Also, the reason I think that people like me are "fired up" is due to the fact that when you hit a brake pedal and nothing happens, you are a bit scared by the whole experience. Engine/computer glitch or not, a vehicle should have primary and secondary braking systems in my opinion. That makes this "glitch" go from an inconvenience to unsafe. Thanks.

 

You are correct in the fact that the truck should be able to sit without the battery going dead. However, the batteries that have been replaced have been so because the battery tested bad. Occassionally batteries have problems like a "Dead Cell" or other isues, just a fact. It doesn't matter the size of the battery, if it goes bad it goes bad and all you can do is replace it.

 

I second the motion that we all understand all cars have issues & 1st releases more so than others but when the issues make the vehicle unsafe to drive- and we see so many of us having the same issues just in this small forum with no way to detail wether or not if because b, e & g happen then a, c, d will also.... things get a little nerve wrecking. You expect or hope to be able to go to the dealer and get answers but when your dealer can't help after your truck's issues put you in a dangerous situation it's not so easy to say I know it's okay b/c the battery has been replaced and no other reasons can be given as to why all the other malarky occurred.
I mean these are new vehicles that I'd guess many of us plan to drive a few more years--with that said hopefully the battery is the only issue for most of us and we can and will be able to drive up to 20k+ miles w/o issues.