Freightliner Action Bulletin
FAB018 - 02/14/03
Air Management Unit (AMU)
The Air Management Unit (AMU) is an assembly of pressure switches and other valves located in a chassis cross-member. It is designed to control the pneumatic accessory functions of a truck using the multiplex electrical system. The AMU was introduced with the launch of the Business Class M2 and is a new development in the industry.
The AMU allows many of the air lines to be removed from the vehicle's dash. This significantly reduces the number of air lines, fittings, and potential leak points within the chassis and dash. By consolidating all valves, pressure switches, and solenoids into modules within the AMU, adding new air options becomes straightforward. The AMU is engineered to serve as a single point of interface for dealers, customers, and body builders.
Air Management Unit (top view)
The image displays the Air Management Unit (AMU) mounted on a blue chassis cross-member. It shows a compact assembly of electrical components, connectors, and wiring harnesses, indicating a centralized control system for pneumatic functions.
The AMU controls various truck functions, including inter-axle and differential traction locks, fifth-wheel slide, pressure protection, air suspension dump, PTOs, engine fan, engine brakes, brake lights, and park brake indicator lamps, among others.
Benefits
- Improved vehicle quality by eliminating many potential leakage points.
- Enhanced vehicle-to-vehicle plumbing consistency or similarity within a fleet.
- Reduces the presence of bulky air lines and valves in the dash.
- Increases ease of serviceability by locating all valves and solenoids centrally, making them accessible for assembly and disassembly.
- AMU modules are available for separate purchase, facilitating easy aftermarket addition of air accessories.
Availability
Included as standard equipment on any Business Class M2 equipped with air brakes or other air-related options.
Further Information
For more details, refer to the Business Class M2 Resource CD or contact Freightliner Sales Engineering.
