Activating anti-theft alarm, function

P80.50-2024-06

Illustrated on vehicle with interior motion sensor (IMS), code 882

A26/14 Interior motion sensor transmitter and receiver

B33 ATA inclination sensor

H3/1 Alarm signal siren with additional battery

N10/6 Left front SAM control module

N10/7 Right front SAM control module

N10/8 Rear SAM control module

N70 Overhead control panel control module

N72/1 Upper control panel control module

N72/1s7 TS, IMS and ATA function indicator switch

N73 Electronic ignition/starter switch control module

S62 Engine hood OPEN and CLOSED switch (ATA)

S17/3 Left door switch

S17/4 Right door switch

S17/5 Left rear door switch
(model 220 only)

S88/3 Trunk lid closing assist locking eye microswitch

S17/6 Right rear door switch
(model 220 only)

The anti-theft alarm (ATA) is activated by:

 Central locking of the vehicle with the remote control key

 Central locking of the vehicle with the lock switches
(model 220 only , )

 The relocking function

 Locking vehicle with KEYLESS GO (only code 889)

 Self-activation (only): Two minutes following the last locking procedure the ATA activates itself if the driver's door is opened and closed again after removing the remote control key.



 The ATA is not activated when the driver's door is open.

 Activation of the ATA interrupts a previously triggered alarm.

 When the power supply is reactivated the ATA is automatically reactivated if it was active before disconnected from the power supply.

 IMS and TS can be switched off separately.

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Function sequence
The EIS control module (N73) transmits the command to the CAN bus to lock the vehicle. The front left SAM control module (N10/6) transmits the message "ATA active" to the CAN bus. Then the affected control modules activate their alarm inputs.

Activating alarm signal siren with additional battery (H3/1)

The front left SAM control module (N10/6) activates the alarm signal siren with additional battery (H3/1) via a direct data bus.

Activating the exterior surface contacts

The rear SAM control module (N10/8) and the front right SAM control module (N10/7) activate the alarm inputs to which the door contacts are connected individually. An input is activated as soon as it has been in the unactuated state for min. 10 seconds.

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Other functions
As soon as the front left SAM control module (N10/6) receives a message from the rear SAM control module (N10/8) via the CAN bus that all doors and the trunk lid are closed the anti-towing sensor (TS) and the interior motion sensor (IMS) are also activated.

 The TS and IMS functions are not activated if they have been switched off previously.

Feedback after successful activation
When the ATA is active the upper control panel control module (N72) causes the indicator LED in the TS, IMS and ATA function indicator switch (N72/1s7) to flash once per second.

 only:

The alarm signal siren with additional battery (H3/1) indicates with a short acoustic feedback signal three times that the ATA has been successfully activated. If a door is not closed while activating the ATA no feedback sounds.

Activating anti-towing sensor (TS)
The front left SAM control module (N10/6) transmits to the rear SAM control module (N10/8) the command to activate the anti-towing sensor.
The TS input is activated by the rear SAM control module (N10/8) as soon as it has been in the unactuated state for min. 10 seconds.

only code 882:
Activating interior motion sensor (IMS)
The front left SAM control module (N10/6) transmits the command to the overhead control panel control module (N70) to activate the interior motion sensor transmitter and receiver (A26/14). The overhead control panel control module (N70) activates the unit via a direct data bus. The unit indicates when it is ready for operation.

 Alarm messages indicated by a unit not capable of operation are ignored by the control module.