I was replacing the parking brake pedal on the wife's '04 yukon XL and noticed what seems to be some kind of port under the dash that runs to a black box zipped tied behind the lower panel. Does anybody have any idea what it is? Thanks!!!
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.


looks like the plug for alarm key. Some of the older alarms had this chip/key that you had to plug in before the car would start. Maybe someone disabled it but left the dock.
it is the port for a disable key. you remove the key to disable and just plug it in when you want to drive off. the dealers put those cheap ass things in in hopes of selling it to you as a theft deterrent. if you opted not to have it, they break off the plastic part off in there and you can drive it. if you get a pick you can pull out the plastic and your truck should not start. you can just yank that crap out.
Wow. Seriously? I've never heard of this. That's totally half-assed and stupid.