Models 129/140
To unlock the pneumatic system equipment (PSE) is actuated by means of a ground signal from the radio frequency/infrared DAS control module.
Model 170
To unlock the multi-function control module is actuated by the RF DAS control module. The multi-function control module then transmits an unlocking signal to the pneumatic system equipment (PSE) via the CAN bus.
The pump motor starts running and supplies pressure. The central locking elements are pressurized. After reaching a pressure of
450 mbar in the system the pressure switch switches off the pump. The pressure in the system is then released via the PSE and the unlocking operation is completed.
The locking operation is accomplished analog to the unlocking procedure. However, the "lock" button is pressed actuating the PSE with ground via the second control line for the radio frequency/infrared DAS control module. The direction of rotation
of the pump motor is reversed providing the vacuum required for locking.