Specifications

19
Testing Testing DAS (Immobilizer) Systems
Note the following when working on DAS 3 systems:
•
The electronic key is completely separate from the remote key access system and does not
require the transmitter battery of the remote control. Instead, it is powered by the EIS, which
means that the electronic key can be used to start the vehicle even if the remote control
battery is dead.
• The side of the electronic key also contains a slide out emergency mechanical key which
allows access to the vehicle if the remote battery is dead. It also can be used to lock the
glove compartment and the trunk.
• The engine control unit (ECU), electronic shift control module (ESM or EWM) and the
electronic ignition control module (EIS) are all locked together permanently.
Workshop Key (Green Key)
A special one-time key from the factory may be necessary under the following conditions:
• when cancelling the disablement of a key track
• after replacing an ECU that is security-related
• after replacing an EIS
For Mercedes Dealers only, a workshop key and EIS are ordered from the factory. The workshop
key and EIS must be ordered together. After installation, the workshop key is then inserted into
the EIS for final programming. Once this procedure is finished, the workshop key is returned to
the factory.
Electronic Steering Lock is optionally available with DAS 3. The steering column is locked and
unlocked by means of an electric motor. The control unit of the electric steering lock is directly
connected to the electronic ignition (EIS) by the CAN bus, which automatically locks the steering
lock when the key is removed and unlocks when the key is inserted. The same setup may be
used on an electronic selector lever on some models.
Keyless Go (Optional)
The optional Keyless Go replaces the DAS 3 electronic key. The first generation Keyless Go
used a chip card carried by the driver which is used to lock or unlock, start and re-lock the
vehicle. The engine is started by pressing a start/stop button on the gear selector lever. A button
on the chip card can be pressed to check whether the vehicle is locked or unlocked. It can also
can be programmed for selective or global locking. The system uses seven frame antennas in
the doors and in the rear of the vehicle to determine the position of the Keyless Go chip to know
where to unlock or lock. The antennas are also used to know if the chip card is internal or
external of the vehicle. This system uses special door handles with pull/push contacts and
Table 4-6 DAS 3 characteristics
Triggered By Signal Type
Authorization
Checked By
Operator
Feedback
Authorized
Start Result
Microprocessor
in key
IR Infrared EIS N73 None
NO fuel injection;
NO ignition
switch;
NO steering lock
release