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Reversing Camera (RFK), Function - GF54.65-P-0005GD

MODEL 204.0/2 with CODE (218) Backup camera except CODE (498) Japan version as of model year 2010/AEJ 09 

MODEL 204.9 up to 31.5.12 with CODE (218) Backup camera except CODE (498) Japan version 

MODEL 204.3 with CODE (218) Backup camera except CODE (498) Japan version 

Fig 1: Reversing Camera - Block Diagram
G10084615

Function requirements, general 

IMPORTANT The electronic ignition lock control unit sends the status of circuit 15 via the interior CAN to the rear SAM control unit.

Reversing camera, general 

The reversing camera function supports the driver when reversing into a parking space by optically recording the road space to the rear of the vehicle and showing it to the driver on the Audio/COMAND display.

Reversing camera function sequence 

When reverse gear or gear range "R" is engaged the reversing camera is powered by the reversing camera power supply module. The reversing camera power supply module is actuated by the rear SAM control unit.

The "reverse gear engaged" status is defined as follows.

Vehicle with transmission 711, 716:

Engagement of reverse gear is defined via the status of the backup lamp switch, which is read in directly by the front SAM control unit.

Vehicle with transmission 722:

The request to engage gear range "R" is defined by the corresponding selector lever position.

The electronic selector lever module control unit sends the selector lever position via drive train CAN, CDI control unit, or ME-SFI [ME] control unit and chassis CAN to the front SAM control unit.

Located in the front SAM control unit are two microprocessors, one for control of basic functions e.g. the exterior lights, and the second for control of the central gateway functions. Both processors communicate with each other internally via interior CAN.

Using all incoming information, the microprocessor which controls the central gateway functions generates the "reverse gear engaged" signal (irrespective of the transmission variant) and sends this signal to the rear SAM control unit over the interior CAN.

The rear SAM control unit then actuates the reversing camera power supply module, which supplies power to the reversing camera.

The pictures recorded by the reversing camera are sent as CVBS signals over the reversing camera power supply module to the COMAND controller unit.

The COMAND controller unit then activates the Audio/COMAND display over the telematics CAN (CAN A).

For vehicles without code (255) AMG Performance Media, the COMAND controller unit sends the picture signals over the low voltage differential signaling (LVDS) line to the Audio/COMAND display.

For vehicles with code (255) AMG Performance Media, the COMAND controller unit sends the picture signals over the low voltage differential signaling (LVDS) line to the AMG Performance Media control unit.

The AMG Performance Media control unit over another low voltage differential signaling (LVDS) line to the Audio/COMAND display.

The Audio/COMAND display then shows the pictures recorded by the reversing camera.

IMPORTANT After reverse gear is disengaged, the reversing camera remains active for t = 15 s (power-down). The power supply is set up by the reversing camera power supply module over the rear SAM control unit with circuit 30.

REFER TO SYSTEM WIRING DIAGRAMS Electrical function schematic, reversing camera Without code (498) Japan version PE54.65-P-2051-97FAB
  Overview of system components of parking assistance systems   GF54.00-P-9997CE