Sprinter 3500 L5-2.7L DSL Turbo (2004)
Air Bag Control Module: Description and Operation
Airbag Control Module
ACM Bracket
The Airbag Control Module (ACM) is secured with three screws to the top mounting surface of a stamped steel bracket that is welded onto the floor
panel within the seat riser underneath the driver side front seat in the passenger compartment of the vehicle. A molded plastic protective cover is installed
over the ACM and secured with integral snap features to a flat metal base plate sandwiched between the bottom of the ACM and the mounting bracket on
the floor panel. This cover is designed to shield the ACM and its wire harness connection from other electrical components and wiring located within the
seat riser area beneath the driver seat, and must always be reinstalled following service removal.
Concealed within a hollow in the center of the die cast aluminum ACM housing is the electronic circuitry of the ACM which includes a microprocessor,
an electronic impact sensor, an electronic safing sensor, and an energy storage capacitor. A stamped metal cover plate is permanently secured to the
bottom of the ACM housing to enclose and protect the internal electronic circuitry and components.
An arrow printed on a label on the top of the ACM housing near the rear provides a visual verification of the proper orientation of the unit, and should
always be pointed toward the front of the vehicle. The ACM housing has integral mounting flanges on three corners. A molded plastic electrical
connector receptacle containing numerous terminal pins is integral to the left facing side of the ACM housing. These terminal pins connect the ACM to
the vehicle electrical system through a dedicated take out and connector of the vehicle wire harness.
The impact sensor internal to the ACM are calibrated for the specific vehicle, and are only serviced as a unit with the ACM. In addition, the ACM must
be electronically programmed for the correct standard and optional supplemental restraint system components installed in the vehicle. The ACM cannot
be repaired or adjusted and, if damaged or faulty, it must be replaced.