Diagnostic Aids
WARNING: This page is about a different car, the 2001 Pontiac Grand Prix, 2001 Pontiac Firebird, 2001 Oldsmobile Intrigue, and 2001 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
Probable causes are malfunctioning pressure sensor or malfunctioning EBCM.