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Home >> Mercedes Benz >> 2012 >> E 350 Cabriolet (207.459) V6-3.5L (276.957) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Antitheft and Alarm Systems >> Description and Operation >> GF80.50-P-2002CA Activate Antitheft Alarm System, Function

GF80.50-P-2002CA Activate Antitheft Alarm System, Function



GF80.50-P-2002CA Activate Antitheft Alarm System, Function
- with CODE (551) Anti-theft alarm system (ATA [EDW])


Function requirements, general
^ Terminal 15C OFF
^ Central locking (CL) functioning properly

Activate antitheft alarm system (ATA), general
The ATA is automatically activated with the CL when the vehicle is locked. The activated ATA is indicated by a permanently flashing anti-theft alarm indicator lamp (S6/1e2) in the instrument panel switch group (S6/1). The antitheft alarm indicator lamp is actuated by the rear SAM control unit with fuse and relay module (N10/2) via the front SAM control unit with fuse and relay module (N10/1).

Before locking the CL on vehicles with code (882) Interior monitoring (only with ATA), the tow-away protection or interior protection can be deactivated.

The ATA function comprises the following partial functions:
^ Function sequence for switching off tow-away protection (with code (882) Interior monitoring (only with ATA))
^ Function sequence for switching off interior protection (with code (882) interior monitoring (only with ATA))
^ Function sequence for activating ATA
^ Function sequence for activating alarm inputs

Additional function requirements for switching off tow-away protection (with code (882) Interior monitoring (only with ATA))
^ ATA not activated

Function sequence for switching off tow-away protection (with code (882) Interior monitoring (only with ATA))
The tow-away protection is switched off by actuating the tow-away protection button (N70/3s9) (model 207.3) o tow-away protection button (S85/2s2) (model 207.4) before locking the vehicle with the CL.

Model 207.3:
The interior protection and tow-away protection control unit (N26/6) directly reads in the status of the tow-away protection button and transmits it to the rear SAM control unit via the rear SAM-LIN (LIN B4). Then the rear SAM control unit deactivates the tow-away protection for the following activation of the ATA.

Model 207.4:
The interior protection sensor (Master) (A26/13) directly reads in the status of the tow-away protection button and deactivates the tow-away protection for the next activation of the ATA.
Then the interior protection sensor (Master) transmits the status "Tow-away protection deactivated" to the rear SAM control unit via the rear SAM-LIN.

Deselection of the tow-away protection is confirmed by an LED in the tow-away protection button for approx. t = 2 s after releasing the tow-away protection button.

Additional function requirements for switching off interior protection (with code (882) Interior monitoring (only with ATA))
^ ATA not activated

Function sequence for switching off interior protection (with code (882) interior monitoring (only with ATA))
The tow-away protection is switched off by actuating the interior protection button (N70/3s8) (model 207.3) or interior protection button (S85/2s1) (model 207.4) before locking the vehicle with the CL.

Model 207.3:
The interior protection and tow-away protection control unit directly reads in the status of the interior protection button and transmits it to the rear SAM control unit via the rear SAM-LIN (LIN ). Then the rear SAM control unit deactivates the interior protection for the following activation of the ATA.

Model 207.4:
The interior protection sensor (master) directly reads in the status of the interior protection button, deactivates the interior protection for the following activation of the ATA and transmits the corresponding request to interior protection sensor (slave) (A26/15).
Then the interior protection sensor (Master) transmits the status "Interior protection deactivated" to the rear SAM control unit via the rear SAM control unit.

Deselection of the interior protection is confirmed by an LED flashing in the interior protection button at a frequency of f = 6.25 Hz (t = 80 ms ON, t = 80 ms OFF) for approx. t = 2 s.

Function sequence for activating ATA
Activation of the ATA comprises the following subfunctions:
^ Function sequence for locking CL via transmitter key (A8/1)
^ Function sequence for locking CL with automatic relocking feature
^ Function sequence for locking CL with Keyless-Go (with code (889) Keyless-Go)

Special case: Driver door
If the driver door is still open when the CL is locked, it is not locked. When the driver door is closed, the alarm input for the driver door is included in the check cycle. This leads to actuation of an alarm when opening the driver door without previous deactivation of the ATA.

Function sequence for locking CL with transmitter key
When the lock button on transmitter key is pressed, a radio signal is sent over the FM, AM and CL antenna amplifier (A2/18) (model 207.3) or via the rear window antenna amplifier (A2/55) (model 207.4.) to the rear SAM control unit.
The rear SAM control unit relays the signal to the electronic ignition lock control unit (N73) via the interior CAN (CAN B). Parallel to the radio signal, the transmitter sends an infrared signal to the driver front door infrared remote control receiver (A26/1) (precise aiming required).
The left front door control unit (N69/1) reads in this signal and sends it to the electronic ignition lock control unit via the interior CAN.
The electronic ignition lock control unit reads in both signals and checks the access authorization for the transmitter key.
If the access authorization is valid, the electronic ignition lock control unit transmits the status "Vehicle locked" via the interior CAN to the rear SAM control unit which activates the ATA.


Function sequence for locking CL with automatic relocking feature
The automatic relocking function is actuated by the electronic ignition lock control unit.
If the vehicle is unlocked and neither a door nor the trunk lid is opened within 40 s, the vehicle relocks automatically.
The electronic ignition lock control unit transmits the status "Vehicle locked" via the interior CAN to the rear SAM control unit, which activates the ATA

Function sequence for locking CL with Keyless-Go (with code (889) Keyless-Go)
On vehicles with code (889) Keyless Go, the CL can be locked with the transmitter key or by touching the outside of the door handle or by actuating the comfort sensor on a door handle.

Detailed information on the function sequence locking/unlocking the CL is given in the separate function description "Keyless Go".

After locking the CL, the electronic ignition switch control unit transmits the status "Vehicle locked" with interior CAN to the rear SAM control unit, which then activates the ATA.

Additional function requirements for activating alarm inputs
^ ATA activated

Function sequence for activating alarm inputs
Activation of alarm inputs comprises the following subfunctions:
^ Function sequence for monitoring switch
^ Function sequence for activating tow-way protection (with code (882) Interior monitoring (only with ATA))
^ Function sequence for activating interior protection (with code (882) Interior monitoring (only with ATA))
^ Function sequence for activating alarm siren (H3/1) (on model 207.3 up to 31.5.10, model 207.3 as of 1.6.10 without code (494) USA version, model 207.4 without code (494) USA version)

Function sequence for monitoring switch
The status of the switches listed above is checked cyclically every t = 200 ms.

If the polls indicate that an input is at rest within t = 10 s, the corresponding input is then armed.
Alarm inputs set later to the non-actuated state (e.g. if the trunk lid is closed only after the vehicle has been locked), are also armed t = 10 s after closing.

Monitored switches:
- Left front door rotary tumbler switch (A85s1) in left front door lock (A85)
- Right front door rotary tumbler switch (A85/1s1) in right front door lock (A85/1)
- Trunk lid rotary tumbler switch (M14/7s1) in trunk lid central locking motor (M14/7)
- Engine hood antitheft alarm switch (S62)

The left front door control unit 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.

The right front door control unit (N69/2) 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 and the status of the engine hood antitheft alarm system switch.

The rear SAM control unit reads in all relevant data and evaluates them accordingly.

Function sequence for activating tow-way protection (with code (882) Interior monitoring (only with ATA))
The tow-away protection is activated (if not previously deselected) after t = 10 s after the closing command from the electronic ignition lock control unit and after the last door or the trunk is closed.
An inclination sensor is integrated into the interior protection and tow-away protection control unit (model 207.3) or interior protection sensor (master) (model 207.4) communicating with the rear SAM control unit or rear SAM-LIN. This inclination sensor determines the reference position, which is compared with the relative vehicle inclination.
Determination of the reference position takes approx. t = 10 up to 15 s. For this purpose an alarm can be actuated approx. t = 30 s after arming at the earliest.
When the maximum vehicle inclination is exceeded with regard to the reference position, an alarm is triggered.

If the vehicle inclination changes very slowly (e.g. leaky tire), the reference position adapts to the current vehicle position to prevent inadvertent activation of the inclination sensor.

If the inclination sensor is defective, all other components of the ATA remain operable.
The corresponding fault codes are stored in the fault memory in the rear SAM control unit.

Function sequence for activating interior protection (with code (882) Interior monitoring (only with ATA))
The interior compartment is monitored by ultrasonic waves on model 207.3 and radar waves on model 207.4.
The interior protection is activated (if not previously deselected) t = 10 s after the last door or the trunk is closed. After another t = 20 s the interior protection is ready for alarm.

The interior protection and tow-away protection control unit (model 207.3) or interior protection sensors (model 207.4) must be calibrated to the interior compartment first.

The interior protection sensors (model 207.4) operate according to the master-slave principle. The interior protection sensor (Master) is located below the center console and monitors the front interior compartment. The Interior protection sensor slave) is located below the rear stowage compartment and monitors the rear interior compartment.

The status of the interior protection and tow-away protection or interior protection sensor (master) is monitored by the rear SAM control unit. If a defect is detected, the remaining ATA functions are still ensured regardless of this error.
The corresponding fault codes are stored in the fault memory in the rear SAM control unit.


Function sequence for activating alarm siren on model 207.3 up to 31.5.10, model 207.3 as of 1.6.10 without code (494) USA version, model 207.4 without code 494) USA version)
The alarm siren is armed together with the ATA and checked cyclically approx. every t = 700 ms by the rear SAM control unit with rear SAM-LIN.

Deactivating ATA:
The ATA is deactivated completely by opening the CL with transmitter key with infrared or radio or by switching on circuit 15C (valid transmitter key in electronic ignition lock control unit). The electronic ignition switch control unit transmits the corresponding signal with interior CAN to the rear control unit, which then activates the ATA.





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