All Terrain Control Module (ATCM)
WARNING: This page is about a different car, the 2014 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The ATCM houses the hill descent switch. The hill descent switch is a momentary contact switch with a LED used to indicate when the system has been enabled. For additional information on the ATCM , REFER to FOUR WHEEL DRIVE (4WD) SYSTEMS , ATCM .