1998 Cadillac DeVille Owner's Manual - Page 293

The cap is behind a hinged door on the dnver's side of your vehicle. The fuel door release button is located to the left of the steering wheel next to the headlamp knob and on the remote keyless entry transmitter. The button only works in PARK (P) when the ignition key is in any position. An alternate fuel door release is located inside of the trunk on the left hand side. Pull it to release the fuel door. While refueling, hang the cap the tether from the by hook on the filler door. To remove the cap,turn it slowly to the left (counterclockwise). The cap has a spring it; if you let in go of the cap too soon, will spring back to the right. it I 6-6