Transmitter/Receiver Module

TRANSMITTER / RECEIVER MODULE







On E36 and E34 models the module is positioned near the steering column under the dash. The module is located in the steering column cover in the E38 and E31.

It includes an inductive coil (ring antenna) that is installed around the lock cylinder. The inductive coil provides a power supply for the transponder and also enables data transfer to occur.

The functions of the transmitter/receiver module are to supply a power source for the transponder and to control the flow of data between the transponder and EWS II control module. The coil of wire receives an A/C voltage from the transmitter/receiver module when KL R is switched on.







The A/C voltage and coil react as a transformer and supply operating power to the transponder chip. Data transmission between the transponder and receiver module takes place over a radio frequency (RF) 125 KHz amplitude modulated AM signal.

The transmitter/receiver module is linked to the EWS II control module through a single wire bi-directional data interface. The transmitter/receiver module converts the AM data signal from the transponder into a digital output signal that is sent to the EWS II control module.