Anti-theft alarm system trigger, function

Function requirements, general

 Antitheft alarm system (ATA) activated

Anti-theft alarm system alarm triggering, general

If one of the alarm inputs of the activated ATA [EDW] exits its non-actuated state, an alarm is triggered.

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 Alarm actuation in the event of undervoltage

The operating voltage range of the ATA [EDW] is defined from U = 8.5 to 15.5 V. If the voltage drops below U 8.5 V, it is no longer possible to trigger a visual alarm output. Only an acoustic alarm is output. The battery voltage is stored in the ATA alarm memory in the rear SAM control unit with fuse and relay module (N10/2).

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The ATA [EDW] alarm triggering function comprises the following subfunctions:

 Function sequence for alarm actuation by opening door, engine hood, trunk lid (model 204.0/3) or liftgate (model 204.2/9)

 Function sequence for alarm actuation by changing vehicle inclination (with code (882) Interior monitoring (only with ATA [EDW]))

 Function sequence for alarm triggering by motion in interior compartment (with code (882) Interior monitoring (only with ATA [EDW]))

 Function sequence for alarm actuation resulting from communication loss to alarm siren (H3/1)
(up to 31.5.10 and as of 1.6.10 without code (494) USA version)

 Function sequence for alarm triggering by emergency opening
(on model 204.0/3 with code (494) USA version)

 Function sequence for alarm output

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Function sequence for alarm actuation by opening door, engine hood, trunk lid (model 204.0) or liftgate (model 204.2/9)

The rear SAM control unit actuates an alarm as soon as the non-actuated state of one of the following switches is interrupted for t > 0.5 s:

- Engine hood switch pedestrian protection + ATA Hall sensor (A38/1) (with code (U60) Pedestrian protection)

- Left front door rotary tumbler switch (A85s1)

- Right front door rotary tumbler switch (A85/1s1)

- Left rear door rotary tumbler switch (A85/3s1) (with model 204.0/2/9)

- Right rear door rotary tumbler switch (A85/4s1) (with model 204.0/2/9)

- Trunk lid rotary tumbler switch (M14/7s1) (model 204.0/3)

- Liftgate rotary tumbler switch (M14/7s1) (model 204.2/9)

- Left engine hood contact switch (S62/43)
(without code (U60) Pedestrian protection)

The left front door control unit (N69/1) directly reads in the status of the left front door rotary tumbler switch and transmits it to the rear SAM control unit via the interior CAN (CAN B).

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The right front door control unit (N69/2) directly reads in the status of the right front door rotary tumbler switch and transmits it to the rear SAM control unit via the interior CAN (CAN B).

The rear SAM control unit directly reads in the status of the trunk lid rotary tumbler switch or liftgate rotary tumbler switch and the status of the pedestrian protection Hall sensor + ATA [EDW] engine hood switch (with code (U60) pedestrian protection) or left engine hood contact switch (without code (U60) Pedestrian protection).

On model 204.0/2/9 the rear SAM control directly reads in the status of the rear door rotary tumbler switch.

For a new alarm actuation, the corresponding switch must first change to the non-actuated state (debounce time t = 500 ms). After a non-actuated state of t = 10 s an alarm can be reactuated by the same switch, if an acoustic alarm is not present.

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 If a locked vehicle is unlocked with the mechanical key and the door is opened, the ATA triggers an alarm.

Additional function requirements for alarm actuation by changing vehicle inclination (with code (882) Interior monitoring (only with ATA [EDW]))

 Tow-away protection not deactivated

Function sequence for alarm actuation by changing vehicle inclination (with code (882) Interior monitoring (only with ATA [EDW]))

If the interior protection and tow-away inclination sensor (N26/6) (with code (882) Interior protection (only with ATA [EDW])) in the interior protection control unit detects an alarm-relevant inclination motion around the horizontal vehicle axle of  = 1° to - 1° ( 0.2°), an alarm is output. The corresponding signal is transmitted by the interior protection and tow-away protection control unit via the rear SAM-LIN (LIN B4) to the rear SAM control unit.

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 Alarm is triggered before a wheel looses ground contact when lifting the vehicle.

Additional function requirements for alarm actuation by interior monitoring
(with code (882) Interior monitoring (only with ATA [EDW]))

 Interior protection not deactivated

Function sequence for alarm triggering by motion in interior compartment
(with code (882) Interior monitoring (only with ATA))

When the interior protection and tow-away protection control unit recognizes an alarm-relevant alarm in the vehicle interior, an alarm is output. The corresponding signal is transmitted by the interior protection and tow-away protection control unit via the rear SAM-LIN to the rear SAM control unit.

If on model 204.2/9 glass breakage is recognized via the left rear glass breakage sensor (B39), right rear glass breakage sensor (B39/1) or rear window glass breakage sensor (B39/4), an alarm is output as well.

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 On vehicles with tilting/sliding roof (SR) (with code (414) Power glass tilting/sliding sunroof ) or panoramic roof (with code (413) Panoramic glass sunroof with top sliding sunroof), the interior compartment is not monitored during active rain closing. After closing or after expiration of t = 35 s, the interior protection is reactivated.

Function sequence for alarm actuation resulting from communication loss to alarm siren () (up to 31.5.10 and as of 1.6.10 without code (494) USA version)

The alarm siren is actuated cyclically approx. every t = 700 ms by the rear SAM control unit with rear SAM-LIN. If a reply to this request is not received within t = 1 s by the alarm siren (no communication), the rear SAM control unit and alarm siren trigger an alarm.

If the alarm siren detects a loss in the supply voltage, it also outputs an acoustic alarm automatically.

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An alarm is only repeated if a new alarm event is registered after the active acoustic alarm was terminated.

Function sequence for alarm triggering from emergency opening
(on model 204.0/3 with code (494) USA version)

The trunk lid emergency opening switch (S88/10) ensures that the trunk lid can also be opened from the inside of the trunk lid when the vehicle is locked. The status of the trunk lid emergency opening switch is read in and evaluated by the rear SAM control unit. The ATA [EDW] triggers an alarm when the trunk lid emergency opening switch is actuated.

Function sequence for alarm output

The alarm is output visually via the turn signals and acoustically via the alarm siren (up to 31.5.10 and as of 1.6.10 without code (494) USA version) or left horn (H2) and right horn (H2/1) (as of 1.6.10 with code (494) USA version). In addition the interior illumination is switched on.

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Visual alarm output:

When an ATA [EDW] alarm is triggered, the rear SAM control unit requests the hazard warning flashing function via interior CAN.

The front SAM control unit with fuse and relay module (N10/1) generates a corresponding flasher frequency which is output via the interior CAN. All turn signals are actuated synchronously on the vehicle.

 Detailed information on performing the hazard warning flasher function is included in the function description "Exterior lights, function" in the partial function "Turn signal light actuation, function".

Acoustic alarm output:

When an ATA [EDW] alarm is triggered, the rear SAM control unit on vehicles up to 31.5.10 and as of 1.6.10 without code (494) USA version actuates the alarm siren via the rear SAM-LIN and on vehicles as of 1.6.10 with code (494) USA version transmits the ATA [EDW] status to the front SAM control unit via the interior CAN.

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Then the SAM control unit actuates the horns via the horn relays (N10/1kO).

The interior lights are also switched on by the front SAM control unit.

Abort conditions:

An activated alarm is interrupted by unlocking the central locking (CL) with the transmitter key (A8/1) or by switching on c. 15C (valid transmitter key inserted into electronic ignition switch control unit (N73)).

The electronic ignition switch control unit transmits the corresponding signal with interior CAN to the rear control unit, which then terminates the activated alarm.