Keyless Entry, Transmitter Key Locating Function - GF80.61-D-2015H

MODEL 906.611/613/631/633/635/637/653/655/657/711/713/731/733/735 with CODE (FY9) Keyless entry+slide with CODE (T55) Electrical actuation for right sliding door 

MODEL 906.611/613/631/633/635/637/653/655/657/711/713/731/733/735 with CODE (FY9) Keyless entry+slide with CODE (T56) Electrical actuation for left sliding door 

Position recognition by a locating field 

Courtesy of MERCEDES-BENZ USA

Key locating 

The Keyless Entry control unit (N69/5) receives a signal for locating the transmitter key (A8/1) via the following antennas:

• Keyless Entry right sliding door antenna (A2/101)
• Keyless Entry left sliding door antenna (A2/102)
• Keyless Entry driver door antenna (A2/103)
• Keyless Entry front passenger door antenna (A2/104)
• Keyless Entry load compartment antenna 1 (A2/105)
• Keyless Entry load compartment antenna 2 (A2/106)

On models 906.611/631/711/731 the Keyless Entry load compartment antenna 2 is omitted

These antennas are located in the vehicle so that the current position of the transmitter key can be recognized by comparison of the field strength (position in relation to vehicle).

By evaluating the chronological changes in the field strength it also possible to detect motion of the transmitter key

The following cases must be differentiated:

• Transmitter key outside of vehicle

  Approaching vehicle from side in direction of electric load compartment sliding door (E-LST)

• Transmitter key outside of vehicle

  Approaching vehicle from driver side in direction of driver door

• Transmitter key in load compartment
• Transmitter key in cab
• Increasing distance between transmitter key and vehicle

The key locating operation is accomplished continuously as long as an authentic transmitter key is within range.

After an authentic transmitter key is recognized, the Keyless Entry control unit transmits a corresponding signal to the EIS control module via the CAN B, depending on the location of the key N73