This information is listed in your owner's manual. Don't have one, then get one. Dealer, salvage yard, e-bay, or a Google Search will help you to find an owner's manual.
i have a 2000 cadillac seville and stability system is on.
use a tow dolly or a tow service
P205/70/R15 - Current owner of 1989 Cadillac Sedan Deville & Tires Plus General Service Technician
While any competent shop should be able to service this, a Cadillac dealer will have the most direct experience.
Jagcat71 Hey i pick up a GM Cadillac Deville(1994 thru 2005)Cadillac sSeville(1992 thru 2004) Haynes Repair Manual at AutoZone auto parts store for $17.00 dollars. Manual#38032
Pushing the "OFF" button, and the "WARM" buttons TOGETHER, will read the codes. Pushing the "OFF" and "HI" buttons TOGETHER to clear codes. Assumingthe cause of the light initially to come on, was corrected, the light should go off. Good luck
Dealer service item.
p0412 Secondary air injection switching valve A circuit.
the 96 cadillac has a computer and sensors that control the ride of the cadillac you have a senor going out etc.. you can use your dash to tell you what is wrong it gives and stores all codes for each system , you use the warm and cool buttons to navigate thru the system this is what techs use to fix the car it tells them everything and i mean everthing you can overide and disable systems using the buttons on the dash,,
It is probably your egr valve that needs replaced!
sequence of service
Transmission needs service? Try changing the fluid and re-setting the code with and obd2 diagnostic tool. Or just take it to a descent shop.