ESP BMW 7 SERIES 1995 E38 Drive Away Protection Syst

9
EWS
System Components
Key with Transponder
Four keys are initially supplied with each vehicle.
Each key contains a wireless electronic chip
(transponder chip). The function of the transpon-
der is to receive and transmit data to the EWS II
control module. The transponder contains a
wireless read/write EEPROM in addition to a
small capacitor and coil for self power capabili-
ties.
The functions of the EEPROM are:
• Store codes for key identification, password and changing codes.
• Receive and respond to coded messages from the EWS II control module.
Power for the transponder is produced through the inductive coil and stored in the capac-
itor. Each time the key is inserted into the ignition AC voltage in the antenna ring induces
voltage in the inductive coil.
All keys either with remote or without, includ-
ing wallet and valet keys contain transponders.
8510108
8510107
Key Notes:
Keys have temperature oper-
ating range of -40
0to 800C.
Keys are shock resistant from
a height of 10 meters.
Inductive coil
Capacitor
Read/Write
EEPROM