I drive a 2000 cadillac catera and when I shut the car off, when i turn the car back on, none of the controls for the radio, sometimes the trunk lock button, fuel tank door button will work. Then afte

you have a loose connection check your grounds under the dash an to radio

I wouldnt bank on this but it sounds like a shift syliniod

Fuel door and trunk issues? How about no fog lights and your radio randomly turning off. If you have any of these issues it is the k134 multifunction relay. It controls all of the above.

Its the K134 Multifunction Module. Its located under the drivers side dashbaord...

so you start the car and the radio will not work? but the radio works with he door open and key off? its normal to turn the car off and the radio play until you open the door.

K134 Multifunction relay is on the driver side, inside the dash above the driver's left ankle (area). (2) panels need to be removed below the steering column to access this area. The first is a panel that matches your dash. The second is a cardboard panel with foam padding on it that encompasses the arms holding the brake pedal and accelerator. You'll then need to lay on your back on the floor board, head in first. Look for a gray box about 3" square by 1 1/2" thick. Push it 'up' off of it's mounting bracket to release. Unplug the wiring harness. Plug in new relay and re-mount.

K134 Multifunction relay is under the dash on the driver side. When sitting in driver seat, above your left ankle, it is located behind a cardboard panel. Replacing cures many problems with the Bose radio, sunroof, gas and trunk releases, fog lights.

Change body computer (buy a used one).
Get it programmed by dealer because radio will be locked out.

It is the BCM (Body control module). The radio is married to it via the serial number. You need to replace the module (lower right kick area, pass side in front of front door, behind plastic...aluminum box), and have it programmed to your car through a Tech 2 diag system.....dealer...this unit controls just about everything apart from the brakes, engine and tranny which all have their own computer. You probably have issues with the sun roof if you have this option.

It's the body control module. It's located under the dash to the left of the steering column. I had same problem, went to the junk yard and bought one and the problem went away. Dealer wants $600.00-700.00 for the BCM, I paid $30.00