I have a 2005 GMC & its make is a Yukon 1500 XL 5.3 Vortec @ 250,000 miles on it. I did do a Fixed OBD port 2 on it & it said 0480 fan control or something & I think I also have either bad battery cuz it drains over night, or I might have a parasitc drain somewhere, Fixed passed my battery. but sick of my vehicle being dead the next am after recharging it.
I got too electrical drain I went to 3 electricians and they didnt found anything. So for now I installed power turn off switch like this :
https://www.ebay.com/itm/254402676623?hash=item3b3b94c78f:g:U1IAAOSw54NdtqUn
So when I leave the car for more than 2 hours I just turn off the battery.
The downside is when you turn on/off the battery the computer learns everything from the start, I have old 1998 Jeep so thats not a problem for me, but with newer cars it can be.
