Security Dash Light :crazy:

I have a 99 Yukon 2wd 4 door....My security light comes on randomly. Usually it should turn off after you start up. Mine has been turning off and then coming back on later when I'm driving. Twice, I have tried to start my Yukon and it starts.... and then dies a second later. I have read about the passlock sytems but I just want to know if anyone else has had that issue and what you may have done. When I first got my Yukon, it wouldnt start once and I replaced the fuel pump. Now I'm thinkin it was the security system the whole time.

If your security light is coming on randomly, but your vehicle is continuing to run, maybe the problem is just related to the light and not the security system -- a problem in the instrument cluster for example. If it is a problem in the passlock of the theft deterrent system, but a scan tool is required to test for problems there.

Diagnostic

I had a shop hook it up for a diagnostic check... they showed a security issue was logged in my computer. They said they wont touch it and I would have to go to another shop or a dealership. They thought it could be the ignition switch since they have replace several from Tahoes and Yukons... but it wasn't.

Most dealerships only charge 40 bucks for a diagnostic.
Money well spent in cases like yours.