Diagnostic Trouble Code (DTC) Clearing
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The Automatic Level Control diagnostic trouble codes will clear when the ignition switch has been transitioned from off to on and the conditions that caused the code to set have been removed.