Do cadillac deville 2000 have a cut off line for gas line

What condition are the cables on the car in? They can develope corrosion and become fractured or broken. Check both the positive and negative cables from the battery all the way to the other end where they connect to the motor and block

Sounds like a leak in a vacuum line.

Your throttle body is dirty.

Trans needs to be rebuilt,

the instrument panels on these new cars are integrated units, it sounds like a broken circuit board inside the unit, the whole unit must be replaced as the are not repairable sorry

The anti theft module would have to be removed or unplugged

it is very possible it is a low charge needs freon

the fuel filter is located on the drivers side under neath where the rear seat would be connected to the frame. relieve fuel system pressure,disconnect negative terminal from the battery,raise rear of vehicleand support it securily on jackstands,detach fuel lines from the filter,some have quick connect . squeeze plastic tabs to pull the connector apart,if it has threaded fiting unscrew the fuel line from the filter.

I'd start by tracing the fuel supply and return lines from the gas tank to the engine compartment. Make sure that they are free of kinks or other damage.

Next, check the fuse box and make sure there is power to the fuel pump. Trace the electrical connections leaving the fuel tank and make sure they weren't torn or otherwise damaged by the tire tread.

Hope this helps and good luck!

You have gotten Air into the Fuel line. You really need to let it run for a while and let it work the air out. When it Dies just keep trying to start and you will get the air out.