Help! Engine will not shut off!

I have a 2003 yukon XL. Never had a problem in 2 years until now. Went to start it the other day and it was dead. No interior lights, radio, etc. Jumped it with my other vehicle and it started fine. Went to turn it off, removed the key and engine was still running. Fortunately, the dealer was still open and I drove it over to them. They were all very perplexed. The tech indicated he never saw anything like this before and would need to consult GM today to figure out the problem

Any thoughts on what could be going on? The tech did remove the ignition cylinder and the ignition module and it still continued to run.

Also, if this happens to me when the dealer isn't open, how do I stall the engine?

Not sure exactly what is going on, but if you pull the fuel pump relay the truck will stall.

Just a quick question, do you have a remote starter installed?

Hope this helps.

Got the bad news. A critter apparently decided to take up residence in the fuse box or power distribution box. Built a nest, soiled in there and chewed up some wires. Had to occur over a 48 hour period while the truck was sitting in the garage.

Dealer says I need to replace the fuse box along with the engine wire harness. Didn't realize how expensive those parts are. Fortunately, it looks like my auto policy will cover most of it under compreshensive.

Anyone have any tips to prevent this from happening again? I do live in a rural area surrounded by farms so we especially have problems with field mice.

Get one of those electronic thingies that drive out mice/roaches/insects by emmiting high pitched sounds (safe for humans/dogs/cats) and leave it in the garage on the floor near where you park.