I just purchased a 2008 Tahoe with 50,000 miles. I have had it for less than a month and it has on several occasions completely “died”. All of the indicator lights come on briefly and the thing seems to do a complete “reset”, I.E. it loses ALL power, then comes back to life. The clock and calendar revert back to some baseline date and need to be reset. Up to now I have been able to restart it but tonight (3/9/2018) it remains dead. Has anyone had similar experience and know if there is a cure. I will contact the dealership, but am not confident that they will have an answer based on some of the things that I have already read online.
First thing to do would be to disconnect and clean the battery cables then securely reconnect them. Those small side terminal bolts cause a lot of problems. Check and see if you can twist the cables at all so the move against the bolts, If you can they are not tight enough.
Do the same with the ground connection at the other end of the negative cable.
4 Likes
I agree with oldtimer about checking out the battery
Except for one thing . . . this vehicle uses a top post group 48 battery, not a side terminal
If the battery is over 5 years old, be proactive and replace it, no matter what anybody tells you. Consider it preventive maintenance. If it fixes the problem, good. If not, well, at least you’ve ruled out the battery and won’t have any problems with it for a few years.
If you’re a Costco member, you can buy a group 48 battery there for a very good price, considerably lower than Autozone, for example.
The clock involvement points to a battery or charging system problem.
Thanks to all that responded. Since everyone pointed to the battery as the problem, I took a closer look at it. I found that the battery was not secured down properly and was able to move back and forth about an inch or so during acceleration or braking. This resulted in the positive cable to have a cut through the insulation and to ground out on the battery tray which has a pretty sharp edge to it. The positive cable is a very tight fit which exacerbated the problem. I recharged to battery, secured it UNDER the clamp on the tray and installed a thick piece is plastic hose around the cable to protect it in the future. I am pretty sure this will correct the problem going forward but thinking this may have caused permanent damage to the battery (even though it seems to have taken the charge well. Thanks for your help in pointing me in the right direction.
4 Likes
Good for you for getting to the bottom of it. Good idea to keep on the lookout for any battery related symptoms, battery/charging system warning light turning on the dashboard etc, as that could mean the battery was damaged. But there’s a good chance no battery damage occurred. Happy motoring. Note to self: Improve battery hold down method on my truck 
1 Like
I stand corrected, I didn’t know any GM vehicles used a top post battery, I know all my son in law’s Chevy pickups have been side post.
I can only comment on the GM trucks . . . we hardly have any GM cars in our fleet
Around the 2007/2008 model years, GM transitioned to top post batteries
I can’t be more “specific” because 2007 was a transition year. Both new and old body styles were sold during that model year.
But for the 2008 model year, all the GM trucks had top post batteries
In my opinion, transitioning to top post was one of the smartest things they ever did. Many problems disappeared, along with the side post batteries
Coincidentally, I just saw my son in law today. His previous truck was a 2007 with side post battery and he confirmed his 2017 has a top post.
I think it was really stupid fpr GM to stick with the side post for so long. Caused a lot of unnecessary breakdowns.