Help!! 13 Tahoe electrical problems

Rjschl0

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 battery. 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 and service charging system message was gone but I checked the alternator and battery with a multimeter...all good. Next few weeks no issue 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.

thecardoc3

Rjschl0 said:

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.

What kind of a tool are you using, and where did you get the recommendation to replace the TCM harness?
A wiring issue "could" cause that test to fail, which BTW that's what a trouble code tells you, what test failed and not what part is bad. Was the transmission shifting normally? Was this listed as a historical code and not an active one? The fact that you had to jump start the car is an important piece of information. With low system voltage, and trying to start the car, false codes can often be generated. With poor or low system voltage all bets are off when it comes to computers running tests correctly.

Rjschl0 said:

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.

The charging system is not designed nor intended to charge a dead battery. Yeah it can do it somewhat, but the reality is the battery is likely only getting up to fifteen to twenty percent state of charge. It takes all night on a regular battery charger to fully charge a battery. Combine how this is not getting recharged completely and the fact that you probably have a parasitic drain pulling power from the battery when the car is parked, you are ruining the battery. It will end up getting sulfated and then that will be the end of the battery, but the vehicle problem will still be there. Do you have a volt/ohms/amp meter? Can you connect it in series and measure the current (amperage) that is flowing after the car has been parked for more than ten minutes?