Denali just went crazy on me...

[bell]

ErVikingo...........pm me your email and i can send a pdf file of of the tech data i have on the denali, along with a captured illistration of the key cylinder.
it is definitely the digital system, everything is controlled through the BCM from the key cylinder....
the info may not actually help you with your problem, but will give you an understanding on what wires do what and may help when the dealer explains what they found....

[sluk]

Was OnStar able to run a remote diagnostics on the vehicle?

[RANDY P]

My guess is the keyswitch failed. That's what they do when they go bad.

The BCM is the next issue....(Body Control Module) GM LAN diagnostics sucks.

rjp

[Oracle]

I had a trailblazer that did that once.. the day after I bought it, great!.. and the dashboard would flash all llights once a week I say...POS.. I sold it a few months later

[ErVikingo]

OnStar was able to determine that the crank position sensor was sending a fault code and that the traction control and abs were not working.

The lady on the OnStar spent at least 30 minutes with me telling me what to expect and reading the definition of every fault code. Also made appointment at local dealership, ...

I even got a follow up call from them. Not bad!