Activating anti-theft alarm (ATA), function

P80.50-2002-09

Illustrated on model 210 sedan

A26/1 Left front door IR receiver

A26/2 Right front door IR receiver

A37 PSE control module (combined)

B33 ATA inclination sensor

CAN Controller area network

N10/1 Signal acquisition and actuation module (SAM)

S17/6 Right rear door switch

S17/8 Trunk lamp switch

S62 Engine hood switch (ATA)

S85/2 ATA interior motion sensor/
anti-towing sensor/status indicator switch

S86/1 Left front door lock switch
(, only)

S88/2 Trunk lid lock switch (, only)

1 Remote control key

N69/1 Front driver-side door control module

N69/2 Front passenger-side door control module

N70 Overhead control panel control module

N73 Electronic ignition switch control module

S9/1 Stop lamp switch

S17/3 Left door switch

S17/4 Right door switch

S17/5 Left rear door switch

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
(,  only)

 The relocking function

 Self-activation (only): Two minutes following the last locking procedure the ATA activates itself if a door, the tailgate or the trunk lid is opened and closed again after removing the remote control key.

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

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

 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 PSE control module (combined) (A37) receives the signal to "lock vehicle" via the CAN bus. It then activates its inputs for the exterior surface contacts and the stop lamp switch.

Moreover the PSE module (A37) activates

 the alarm signal siren with additional battery (H3/1)

 the input for the anti-towing sensor (TS)

 only with code 882: the interior motion sensor (IMS)

If the ATA is activated the LED indicator in the ATA anti-towing sensor/status indicator switch flashes (S85/3)



The alarm signal siren with additional battery (H3/1) honks three times when the ATA is activated successfully. No confirmation is given if a door is not correctly closed when the ATA is activated.

Activation of the exterior surface contracts and the stop lamp switch
The alarm inputs to which the contacts are connected are activated individually. An input is activated as soon as it has been in the non-actuated state for at least 10 seconds.

Activation of the anti-towing sensor (TS)
The TS input is activated as soon as it has been in the non-actuated state for at least 10 seconds.

only code 882:

Activation of the interior motion sensor (IMS)
As soon as all doors are closed the IMS transmitter and receiver units are requested to self-activate via the data bus. Each unit confirms that it is operational. Alarm messages sent by a
non-operational unit are ignored.
In vehicles with IMS the ATA interior motion sensor/anti-towing sensor/status indicator switch (S85/2) is installed instead of the S85/3 switch.