1997 Yukon security light off

Gabe187g · January 12, 2017

So my truck has ran great for the year and a half I've owned it, right up until yesterday. The motor turns over, but won't start. One of the first trouble shooting things I saw was to check the "security" light on the dashboard. Then I realized that it's not coming on at all any more. Any ideas? BCM? All fuses are good.

Skweez · February 15, 2017

I'm having the same problem. It's happened multiple times and every time it's because of the BCM. First check your BCM, clean off pins and put some fresh dielectric grease. Not too much. Then put your key in the ignition and try to start it ,once. Then leave the key in the ignition in the on position. Leave like this for at least 15 min. It should reprogram the BCM to accept the key. Turn the key to off then back on and try to start it. Hopefully it worked if not you might have to do it 2-3 times in a row before you try to start. If still no start your BCM might be fried. I've gone through 3 BCM in my 2000 Denali and it's always the same pin and same relay that gets fried. Ifthedamage isn't too bad you can pull the bad relay and solder on a new one, or get a new BCM. The reprogram sequence worked a few times for me but not this last time hope you have better luck.