Hello,
I have a 2000 Cadillac Deville. It doesn't start, or even turn over. The gear shift lever indicates that it is in Drive 4 all the time. I have a Tech II scanner and it says that the transmission is in 2nd gear and the inticator is in Drive 4. The indicator does not change when shifting gears. I jumpered the starter relay, and it turns over, but still won't start. I believe it is the park safety switch. Any other ideas, Thanks Motorzonesuzuki

Sounds like the prndl sensor,it is mounted on the trans linkage where it enters the trans case. Check for any TSB"s regarding this condition.

I found the problem. I removed the bottom pan and found that the rod that runs from the internal mode switch to the parking pawl has a plastic clip broken. Replaced clip, and now works great.