E 420 (210.072) V8-4.2L (119.985) (1997)
Pump: Description and Operation
As of 6/96 Production (DAS X)
Purpose
Provide vacuum and pressure
Design
The pneumatic system equipment control module has electrical as well as pneumatic connections. A pump motor and pressure switch are located
in the housing
Function
Model 129
To unlock, the pneumatic system equipment (PSE) is actuated by the IR DAS control module
Models 140/202
To unlock, the pneumatic system equipment (PSE) is actuated by the IR DAS control module via a ground signal.
Model 210
To unlock the multi-function control module is actuated by the IR DAS control module. The multi-function control module then sends the signal to the
PSE control module via the CAN bus.
The pump motor starts running and supplies pressure. The CL actuators are pressurized. When a pressure of 450 mbar is reached in the system the pump
is switched off by the pressure switch. The pressure in the system is then released by the PSE and the unlocking operation is completed.
The locking procedure is accomplished analog to the unlocking operation. However the next time the remote control button is pressed the PSE is also
actuated by connecting it through to ground by the second control lead on the IR DAS control module. The direction of rotation for the pump motor is
reversed thereby providing the vacuum required to lock.