A Cadillac’s computer controls the emissions system and other vital systems on the vehicle. When there is something wrong with the Cadillac, the computer will generate and store a fault code. You’ll need to run a diagnostic test to figure out what is wrong with the vehicle. Once you’ve fixed whatever is wrong, you need to reset the Cadillac’s computer.
Step 1: Open the fuse panel under the steering column by pulling down on it with your fingers.
Step 2: Locate the fuse for the Cadillac’s computer. This fuse will be labeled “ECU,” for “electronic control unit.”
Step 3: Pull the ECU fuse using the fuse pullers in the fuse panel.
Step 4: Turn the ignition key to the “on” position but do not crank the engine. Wait 5 minutes and replace the ECU fuse. The computer will reset itself.