I have a 2013 Tahoe with 190000 miles on it. About a 6 months ago I had to get it jumped cuz I thought I left the interior lights on and it drained the batter. When jumped, it said service charging system in the dash. Drove the high way for awhile and turned it off and let it sit for about 30 mins went back out and started right up service charging system message was gone but I checked the alternator and battery with a multimeter...all good. Next few weeks no issue and but the service airbag light and msg would come on intermittently. I live in nebraska so it gets cold and I just figure it was a sensor issue due to weather since it wouldn't stay on long. A month later, my rear hvac wasn't turning to heat for a day. Next day it was fine. And hadn't had a problem since. A few other times it wouldn't start, had to jump it. Took the battery in for a test. Good battery. Took the alternator in for test..good alternator. So for the past month I'd drive it and all would be good but then I'd wake up and it be dead. Jump fine, pulling right volts. Be good for 3-7 days then dead again. Today, I go out won't start so I Jump it and the check engine light is on but no message. Read the code and it says P2534: Ignition On/Start Switch Circuit Low Voltage and a recommendation of replacing the tcm wiring harness. I drive it 50 miles park it and leave for about an hr and half come out starts right up and check engine light is off. I looked it up and few people said they had similar issues and it was a bad ground. Checked all the grounds l, they are fine, I checked for shorts in the fuses, nothing. Help me please. I'm exhausted.