Draining Battery/No Start 07 Tahoe

[rffanat1c]

I recently bought a used 07 Tahoe LTZ. Two times now I've had the vehicle off but the radio on and go to start it 15 minutes later and it won't start. Clock resets to 12:00 and cd changer and locks go bezerk. The other time this happened, my wife parked it for 4 hours with the key out and everything off. She came out to the vehicle and it was dead again and wouldn't take a jump start. The other two times it took a jump and started.

I've taken it to the dealership and they said the 07033 service bulletin (BCM Flash) has already been done and they then re-flashed the rear heated seat module. They also did a test on the battery and said it was fine, had almost all of its original cranking amps and only had a 0.1 amp draw when off.

I went out to the vehicle today to do a test and just turned the radio on and sat in the car for 15 minutes and the voltage gauge eventually dropped to just above 9. I went to start it and it was dead, lights and radio worked but it wouldn't start. Just before I tried this, the Stability Track light came on and it said the system was off. I turned the key, no start and the the radio reset to 12:00 and the cd changer went nuts. I've researched this to death on the issue and no one can seem to give me a clear answer. Thanks for any help anyone can provide. I'm going to try a new battery tomorrow but don't have high hopes.

 

[clkelley]

Welcome to the neighborhood!

Everything going crazy is a result of a low voltage condition through the ignition module more than likely. But the battery draining so fast when listening to the radio is one that has me stumped as well, my wife's 04 Denali does the same thing. Not sure what would cause the situation when your wife parked it and it drained unless she possibly wound up leaving the interior lights on without realizing it?

 

[brsimp8]

Battery

Hello, did you purchase a new battery and did it work? I am having the same issue. Thanks,
Brad

 

[jweezy]

go to gm have tsb battery drain update completed

Hello, did you purchase a new battery and did it work? I am having the same issue. Thanks,
Brad

I had same issue with battery drain. Went to the GM Dealership they ran my Vin found TSB pertaining to issue did the Computer Update and I am good to go now. I also had the biggest battery Walmart could put in which was 700 the stock is 600cca. The dealership did a courtesy battery check and found that my battery was weak and had an internal short. These vehicles use a lot of juice, so go get the battery rundown update done and get a 700 cca battery installed. I believe Walmart was $88.00