GF32.22-P-4005E Level Adjustment, Function
GF32.22-P-4005E Level adjustment, function
- with CODE (489a) Airmatic (semi-active air suspension)
The AIRmatic at front and rear axle is a fully load-bearing suspension system. It maintains a constant vehicle level when the engine is running, irrespective of the load. This is achieved by the air compressor pumping air through the valve units into the suspension struts until the vehicle level has stabilized. The vehicle level is determined by two level sensors at the front axle, and one at the rear axle and sent to the AIRmatic control module.
A valve unit is integrated into each suspension strut. A level valve in the valve unit and a pressure reduction valve at the compressor unit regulate the vehicle level.
A central reservoir for compressed air permits regulation of the vehicle level even when at a standstill. Moreover, the adjustment of the vehicle level is decoupled from the air compressor.
Locking function
If the control module detects that all wheels are unloaded when the vehicle is stationary, the valves of the sprint struts are closed. The vehicle therefore remains at the current level. This is essential, for example, when changing a wheel or during repair work (lifting platform).
Normal function (engine is running)
When at a standstill, the level is readjusted after opening a door or the luggage compartment lid in the event of a deviation of more than ± 10 mm.
While moving, the level is readjusted in the event of a deviation of more than ± 20 mm. Every 15 min there is a level equalization to ± 10 mm.
Depending on the situation, pressure can be produced by the compressor or the pressure reservoir of the central reservoir in order to raise the vehicle. Pressure from the reservoir is used when the vehicle is stationary to minimize noise. If a particularly high level of pressure is required, pressure can also be delivered by the compressor and by the central reservoir simultaneously.
When the vehicle is loaded, the lowering of the vehicle level by the level sensors is detected by the control module. By activating the solenoid valves, air is delivered to the suspension struts of the front wheel in question or the rear axle until the vehicle level has reached its specified value.
When unloading the vehicle, the pressure reduction valve is opened in addition to activating the respective wheel valve.
Wake-up function (function duration approx. 1 min.)
Using the remote control, the door contact switch or the switch for luggage compartment illumination, the AIRmatic control module with ADS is "woken up" in order to check the instantaneous vehicle level for critical states (level too low) and, if necessary, to raise the vehicle or to lower it when unloading.
If the vehicle level is lowered by more than 30 mm, it is raised by the reservoir to the normal level (only with reservoir pressure greater than 11 bar). With a vehicle level of less than -65 mm, it is raised even with a reservoir pressure of less than 11 bar by the compressor from the "critical range" to -63 mm (prerequisite: battery voltage greater than 12.4 V).
If the vehicle level is raised when unloading by more than 10 mm, it is lowered to the normal level by reducing the pressure.
Lifting the vehicle is not possible using the level control switch.
Function in the case of vehicle status "ignition ON"
Same function as for wake-up function, but without time limit.
Engine-off function (function duration approx. 1 min.)
After switching off the ignition, the control module records level changes in order to be able to readjust the vehicle level in the event of any loading or unloading operations (raise or lower). (Same function as for wake-up function).
