Anti-Theft Alarm System - SMART 453 Series Introduction Into Service Manual

Anti-theft alarm system

Anti-theft alarm system (ATA)
An anti-theft alarm system is available as special equipment
in the new smart.
The customer can choose between two variants of the anti-
theft alarm system.
• Anti-theft alarm system (code V19)
• Anti-theft alarm system with interior monitoring and tow-
away protection (code 885)
On vehicles with code (V19), the SAM control unit is the mas-
ter control unit for the anti-theft alarm system.
If the vehicle is locked with the transmitter key, the anti-theft
alarm system function is activated.
When armed, the SAM control unit monitors the central lo-
cking microswitches of the vehicle doors, the liftgate and the
ATA switch on the battery. If it detects a status change in the
central locking microswitches or ATA switch on the battery, it
actuates the turn signal lights and the horn.
Vehicles with code (885) are equipped with ultrasonic
sensors in the interior, a sensor for tow-away protection, a
battery-buffered alarm horn and a controller unit.
Tow-away protection
If the position of the vehicle is changed, the ATA inclination
sensor detects this and sends a message to the ATA control
unit, which then triggers the alarm.
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– This printout will not be recorded by the update service. Status: 06/2014 –
Interior protection
Interior protection is activated approx. thirty seconds after
the vehicle is locked.
Using the ultrasonic sensors mounted centrally on the headli-
ner of the vehicle, the ATA control unit monitors the incoming
and outgoing wave patterns. If anything enters the vehicle wi-
thout authorization, these change significantly and an alarm
is triggered.
Alarm output
The alarm is output via the battery-buffered alarm horn.
Drive authorization system
The drive authorization system of the new smart represents a
system network of the following components:
• Center SAM control unit (N10/10)
• Transponder coil (L11)
• Vehicle key (A8/1)
• ME-SFI [ME] control unit (N3/10)
• Electronic Stability Program control unit (N30/4)
• Dual clutch transmission control unit (N15/13) (with au-
tomatic transmission)
If the key is turned to the position "Ignition ON" in the ignition
lock, data is exchanged between the vehicle key and the
transponder coil. The center SAM control unit receives the
data of the vehicle key from the transponder coil and evalua-
tes it.
At the same time, the center SAM control unit initiates au-
thentication of the Electronic Stability Program control unit
and the dual clutch transmission control unit via CAN bus.
If the authentication of both control units is successful and
the vehicle key is recognized as belonging to the vehicle, the
center SAM control unit sends an enable signal to the engine
control unit. The vehicle can now be started.
Introduction of the New smart fortwo coupé and smart forfour | Model Series 453