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Emergency alarm function - GF82.25-P-2011LE

MODEL 221.0/1 with CODE (965) Electrical preinstallation for rental vehicles with CODE (934) Taxi emergency alarm system as of model year 2009/YoM 08 

Function requirements, general 

Emergency alarm, general 

The emergency alarm function is a protective device for the taxi driver. The emergency alarm can be triggered by the taxi driver if he/she feels threatened by someone. At the same time, a radio help call can also be triggered.

The emergency alarm function consists of the following partial functions:

Function sequence for emergency alarm 

The emergency alarm can be activated via the taxi emergency alarm system radio remote triggering transmitter (A8/4) (full alarm) or via the emergency alarm system activation button (S62/6) concealed in the driver footwell.

An active emergency alarm is ended by pressing the emergency alarm system cancel button (S62/5).

IMPORTANT Depending on the programming, a radio help call can also be triggered.

The following variants of the emergency alarm can be output:

Function sequence for silent alarm 

The silent alarm should prevent the threatening person from noticing the alarm triggering.

The silent alarm is requested by pressing the emergency alarm system activation button once. The special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) reads in the status of the emergency alarm system activation button directly, evaluates this and actuates the roof sign lamp (E14/4) (with code (342) Roof sign connection for taxi) with a frequency of f = 2.5 Hz.

Function sequence for full alarm 

With a full alarm, the interior illumination (IBL) is statically actuated and the exterior lights (ABL) are actuated to flash in addition to the output of the silent alarm.

The full alarm is requested by actuating the "Trigger" button or the radio remote triggering transmitter twice within t = 3 s requested.

The multifunction control unit reads in the status of the emergency alarm system activation button directly.

The request for full alarm via the radio remote triggering transmitter is received by the multifunction control unit via the following route:

IMPORTANT For safety reasons, the request for the full alarm via the radio remote triggering transmitter is automatically repeated after t = 30 s.

The multifunction control unit evaluates the request and sends corresponding information on the output of the full alarm via interior CAN to the front control unit, which then evaluates this and initiates the output. To do so, it sends the corresponding information via interior CAN to the following control units:

IMPORTANT Detailed information on the actuation of individual components of the IBL can be found in the separate function description Interior illumination (IBL) function.

During output of the full alarm via the exterior lights, the following functions are actuated to flash:

IMPORTANT Detailed information on the actuation of individual components of the exterior lights can be found in the separate function description Exterior lights function.

In addition to the visual output of the full alarm, the front SAM control unit actuates the left horn (H2) and the right horn (H2/1) with a frequency of f = 1.6 Hz.

Function sequence for radio help call 

Depending on the programming, a radio help call can be made separate from or together with the emergency alarm.

The radio help call is started by:

The request for the radio help call is recognized by the multifunction control unit and forwarded to the two-way radio (A49) (accessories) or the radio data transmission two-way radio (A49/5) (accessories).

The two-way radio or radio data transceiver forwards the signal to the telephone and GPS roof antenna (A2/49) to be sent.

The radio help call is then made via the multifunction antenna to the taxi main office.

Depending on the programming, the actuation of a radio help call can occur "statically" or as a "pulse".

With the "static" actuation, the discrete output at the multifunction control unit is switched to ground when a radio help call is made until the request for the radio help call is reset via the emergency alarm system activation button.

With the "pulse" actuation, the discrete output at the multifunction control unit is switched to ground twice for t = 1 s when the radio help call is made, with a break of t = 1 s between the pulses.

An active radio help call is ended by pressing the emergency alarm system cancel button. Often, however, it is necessary to restart the two-way radio in order to reset the radio help call in the two-way radio.

Function sequence for display of fault messages 

The fault messages are displayed in the multifunction display (A1p13) of the instrument cluster (A1).

Faults and malfunctions that occur are recognized by the multifunction control unit, stored and sent via interior CAN, central gateway control unit (N93) and central CAN (CAN F) to the instrument cluster.

In addition, the multifunction control unit cyclically sends data protocols to the instrument cluster.

The following faults and malfunctions are shown in the multifunction display:

IMPORTANT During diagnosis using the diagnostic tester, a corresponding message is also shown in the multifunction display.

REFER TO SYSTEM WIRING DIAGRAMS Electrical function schematic for emergency alarm   PE82.25-P-2060-97SAA
  Component description for instrument cluster A1
Model 221.0/1 (except model 221.095/195)		 GF54.30-P-6000LE
Model 221.095/195 GF54.30-P-6000LEH
  Component description for front SAM control unit with fuse and relay module N10/1 GF54.21-P-6070LE
  Component description for rear SAM control unit with fuse and relay module N10/2 GF54.21-P-6030LE
  Special vehicle multifunction control unit (SVMCU [MSS]), component description N26/9 GF54.21-P-4010LEA
  Left front seat control unit, component description N32/1 GF91.29-P-5230LE
  Right front seat control unit, component description N32/2 GF91.29-P-5240LE
  Component description for left front door control unit N69/1 GF72.29-P-4141LE
  Component description for right front door control unit N69/2 GF72.29-P-4142LE
  Rear door control unit, component description N69/3, N69/4 GF72.29-P-6020LE
  Component description for overhead control panel control unit N70 GF82.20-P-5216LE 
  Upper control panel control unit, component description N72/1 GF54.21-P-6040LE
  EZS control unit, component description N73 GF80.57-P-6003LE
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