I have a 2002 Cadillac deville and sometime it idle up on his own

It appears to be year specific.

https://www.gmpartsdirect.com/v-2002-cadillac-deville--dts--4-6l-v8-gas/electrical--sunroof

https://www.google.com/search?q=2002+Cadillac+Deville+replacement+sunroof

And dropping the year from the Search Query.

https://www.google.com/search?q=Cadillac+Deville+replacement+sunroof

That is the compressor for the rear air shocks. If you stop hearing this noise then something is wrong. It levels the car when running.

the spec. is 41-47 psi at idle
http://www.ericthecarguy.com/forum/8-Service-and-Repair-Questions-Answered-Here/25682-2002-cadillac-deville-possible
fuel-pump-failure

Try filling it with a top grade premium gas.

No screw - fully computer controlled. Also, there is no idle control sensor - just a throttle position sensor (TPS) and an idle air control (IAC) motor. If you are replacing the IAC, clean the throttle body ports VERY carefully using a recommended solvent.

see last answer

Sticking throttle plate maybe , clean with carb. cleaner .
2002 Saturn high idle at red light
007 Idle Speed Problems Scan Data for Idle

check to make sure you have no vacuum hoses off or damaged ones loss of vacuum can cause hi idle and loose power and fuel consumption.

throttle position sensor. or idle control sensor

have throttle position switch checked and idle control valve checked.