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Anti-theft alarm system trigger, function - GF80.50-P-2004GN

MODEL 166 as of model year 2016 with CODE 551 (Anti-theft warning system) 

MODEL 292 with CODE 551 (Anti-theft warning system) 

Function requirements, general 

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.

IMPORTANT Alarm actuation in the event of undervoltage

The operating voltage range of the ATA [EDW] is defined from U = 8 to 16 V. If the voltage drops to U ≤ 8 V, a visual and acoustic alarm output are no longer required.

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

Function sequence for alarm triggering by opening a door, tailgate or engine hood 

The SAM control unit (N10) actuates an alarm so soon as the one of the following switches exits the non-actuated state:

The left front door control unit (N69/1) directly reads in the status of the left front door safety catch microswitch and transmits it to the SAM control unit via interior CAN (CAN B).

The right front door control unit (N69/2) directly reads in the status of the right front door safety catch microswitch and sends this via the interior CAN to the SAM control unit.

The left rear door control unit (N69/3) directly reads in the status of the left rear door safety catch microswitch and sends it via interior CAN to the SAM control unit.

The right rear door control unit (N69/4) directly reads in the status of the right rear door safety catch microswitch and sends it via interior CAN to the SAM control unit.

The rear door control unit (N10/8) reads in the status of the liftgate rotary tumbler switch and transmits it to the SAM control unit over the interior CAN.

The SAM control unit directly reads in the status of the left engine hood contact switch.

The SAM control unit evaluates the status of all alarm inputs.

To trigger a new alarm, the corresponding switch must first change to the non-actuated state.

After a non-actuated state of t = 1 s an alarm can be reactuated by the same switch, if an acoustic alarm is not present.

IMPORTANT If a locked vehicle is unlocked with the emergency key and the door is opened, the ATA [EDW] triggers an alarm. The electronic ignition lock control unit (N73) transmits the status of the central locking (CL) to the SAM control unit via the interior CAN.

Additional function requirements for alarm triggering by changing the vehicle inclination (with CODE 882 (Interior monitoring)) 

Function sequence for alarm triggering by changing the vehicle inclination (with CODE 882 (Interior monitoring)) 

If the inclination sensor integrated in the ATA [EDW]/tow-away protection/interior protection control unit (N26/6) recognizes an alarm-related change of inclination, an alarm is output.

The ATA/tow-away protection/interior protection control unit sends the request to output an ATA over the interior CAN to the SAM control unit.

Actuation criterion:

Changing of the vehicle inclination (on the horizontal axis) by approx. ≥ 1°

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

Additional function requirements for alarm triggering by movement in the vehicle interior (with CODE 882 (Interior monitoring)) 

Function sequence for alarm triggering by movement in the vehicle interior (with CODE 882 (Interior monitoring)) 

The left interior protection transmitter (N26/6b1) and the right interior protection transmitter (N26/6b2) send ultrasonic signals in the vehicle interior. The ultrasonic signals are received by the interior protection receiver (N26/6a1).

If a movement in the vehicle interior is recognized and considered to be alarm-relevant, an alarm is output.

The ATA/tow-away protection/interior protection control unit sends the request to output an ATA over the interior CAN to the SAM control unit.

IMPORTANT In vehicles with CODE 414 (Sliding roof) or CODE 413 (Panoramic sliding sunroof), no monitoring of the vehicle interior takes place during active rain closing. After closing or after expiration of t = 35 s, the interior protection is reactivated.

In vehicles with CODE 890 (EASY-PACK liftgate), the interior protection is deactivated when the liftgate is opened with the transmitter key (A8/1). The interior protection is activated during comfort closing, however the vehicle interior is not monitored.

Function sequence for alarm triggering by glass breakage (with CODE 882 (Interior monitoring)) 

The ATA [EDW]/tow-away protection/interior protection control monitors the status of the following sensors:

If the ATA [EDW]/tow-away protection/interior protection control unit recognizes an interruption of the contact loop incorporated in the glass in the corresponding rear side window, an alarm is output.

The ATA/tow-away protection/interior protection control unit sends the request to output an ATA over the interior CAN to the SAM control unit.

IMPORTANT After an alarm is triggered by a glass breakage sensor (on model 292), the other glass breakage sensors (on model 292) are deactivated (series circuit).

Function sequence for alarm triggering from communication loss to alarm siren (without CODE 494 (USA version)) 

The alarm siren is actuated cyclically approx. every t = 600 ms by the ATA [EDW]/tow-away protection/interior protection control via the alarm system LIN (LIN B14). If a reply to this request is not received within t = 1 s by the alarm siren (no communication), the ATA [EDW]/tow-away protection/interior protection control trigger an alarm.

The ATA/tow-away protection/interior protection control unit sends the request to output an ATA over the interior CAN to the SAM control unit.

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

IMPORTANT An alarm is only repeated if a new alarm event is registered after the active acoustic alarm was terminated. Three or ten alarms can be output during an arming cycle depending on the national version.

Function sequence for alarm triggering by panic switch (with CODE 763 (Radio remote control with panic switch)) 

Vehicles without CODE 889 (KEYLESS-GO) and without CODE 893 (KEYLESS-GO start function) 

When the panic alarm button on the transmitter key is pressed for t ≥2 s, it sends a radio signal (access authorization code) over the rear window antenna (A2/32) and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier (A2/18) to the electronic ignition lock control unit.

Vehicles with CODE 889 (KEYLESS-GO) or CODE 893 (KEYLESS-GO start function) 

When the panic alarm button on the transmitter key is pressed for t ≥2 s, it sends a radio signal (access authorization code) over the rear window antenna and the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier to the KEYLESS-GO control unit (N69/5). The KEYLESS GO control unit transmits the access authorization code to the electronic ignition lock control unit via interior CAN.

Parallel to the radio signal, the transmitter key transmits an infrared signal via the driver door infrared remote control receiver (A26/1) (precise aiming required) and a direct line to the left front door control unit. The left front door control unit transmits this to the electronic ignition lock control unit via the interior CAN.

IMPORTANT The infrared and radio signals include the same information (redundant); the first signal received is accepted. This function serves for operating safety in the event that the radio signal is blocked by interference such as electromagnetic fields.

The electronic ignition switch control unit checks the access authorization of the transmitter key.

If the access authorization is valid, the electronic ignition lock control unit transmits the "Activate panic alarm" request via the interior CAN to the SAM control unit. The SAM control unit actuates an ATA [EDW] alarm.

IMPORTANT The panic alarm is interrupted when the panic alarm button on the transmitter key is actuated briefly. The function sequence "Interrupting panic alarm" is the same as for "Actuating panic alarm". Aborting also occurs by inserting the key in the electronic ignition lock.

Function sequence for alarm output 

Visual alarm output 

When an ATA alarm is triggered, the SAM control unit activates the hazard warning flasher function via interior CAN.

All turn signals are actuated synchronously on the vehicle.

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

Moreover, the SAM control unit switches on the interior illumination.

IMPORTANT Detailed information on implementation of the interior illumination is given in the function description "Interior illumination (IBL) function".

Acoustic alarm output 

The acoustic alarm is output on vehicles without CODE 494 (USA version) by actuating the alarm siren and on vehicles with CODE 494 (USA version) by the left horn (H2) and right horn (H21).

The alarm siren is actuated by the ATA/tow-away protection/interior protection control unit via the alarm system LIN.

The horns are actuated by the SAM control unit via the horn relays (F58kJ).

IMPORTANT The acoustic alarm is activated for t = 30 s and the optical alarm for t = 300 s. On vehicles with code (833) Great Britain version, the acoustic alarm is extended to t = 300 s under the following conditions:

IMPORTANT The alarm output is interrupted by opening the CL via infrared or radio or by switching on circuit 15C. The electronic ignition lock control unit transmits the status of the CL [ZV] and the status of circuit 15 via the interior CAN to the SAM control unit, which then terminates the active alarm.

Electrical function schematic for anti-theft alarm system, alarm actuation PE80.50-P-2053-97NBA
Overview of system components for theft protection and locking GF80.00-P-9999GN 
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