Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
2005 Cadillac DeVille Problem Reports
Most Reported 2005 Cadillac DeVille Problem Reports
The steering wheel position sensor may fail, resulting in the service stability message being displayed.
One or both transmission output shaft seals may leak. Our technicians tell us that worn bushings inside the transmission could be the cause of the damaged seals. Our technicians tell us that if a bushing is worn, excess play will be noted where the drive axle attaches to the transmission.
This powertrain control module (PCM) may develop a fault with its electrical ground location at the front of the engine block near the starter motor.
under the front left fender/bumper area, there is a electric pump that pushes air into the catalytic converter. It runs for about 45 seconds when you start you car and once in a while there-after. The bearings went out in mine and I tried to repair it, but ended up replacing it. After 8 months, the new one failed. The GM dealer warrantied it and I replaced it again, which now has stopped working again.