My Service Stability Steering light is popping up on my control menu. I have been reading on here that the cause my be that me Steering Sensor is out. I have recently also been having trouble with control. What I mean by that is going over bumps the rear of the car tends to shift to one side quickly and also very bouncey ( up and down). I thought maybe my rear struts were bad but when I called a local parts store they no rear struts for my car. Please help I don't have a lot of extra money but I need to solve both of these problems. My Bonneville is an 2002 SSEI. Any information would be helpful!!
Thank You,
Rachel

Your car does not have struts for the rear - it has shocks. The auto parts store should have been able to tell you that. The back end being bouncy and kicking out like that is a good indicator of bad shocks. A need for a 4 wheel alignment will also cause the side stepping, but not the bouncing.

The steering position sensor is the mostly likely cause for the service stability system warning on the DIC.

Edit - After reading Toasty'* and Darcy'* posts in your other locked thread http://www.bonnevilleclub.com/forum/...ic.php?t=84428 it reminded me of something. Do these events coincide? Does the service stability system warning come on after hitting a sharp bump, or does it happen at any time? Before I changed my rear shocks, if I hit a sharp bump with the right rear, it would set that warning. Having the car scanned, as suggested, is a good idea to find out what is happening