Circuit/System Description
WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The automatic level control (ALC) adjusts the vehicle suspension ride height. The electronic suspension control (ESC) module determines the height of the vehicle based on the voltage from the ALC sensor. The ESC module grounds the ELC COMP relay and the exhaust control solenoid to raise and lower the vehicle in order to keep the vehicle level.