Reversing camera (RFK), function - GF54.65-P-0005CEJ
MODEL 204.0/2 up to 28.2.11
with CODE (218) Reversing camera
with CODE (498) Japan version
as of model year 2009
/YoM 08
MODEL 204.9
with CODE (218) Reversing camera
with CODE (498) Japan version
Function requirements, general
- Circuit 15 ON
- Trunk lid (model 204.0) or liftgate (model 204.2/9) closed
- Reversing camera function activated through the COMAND controller unit
- Drive position "R" engaged
The electronic ignition lock control unit sends the status of circuit 15 via the interior CAN to the reversing camera control unit. The trunk lid rotary tumbler switch (model 204.0) records the status of the trunk lid. The liftgate rotary tumbler switch (model 204.2/9) records the status of the liftgate.
The rear SAM control unit reads in the status of the trunk lid rotary tumbler switch or the liftgate rotary tumbler switch directly and then sends it over the body CAN to the reversing camera control unit.
If the trunk lid or liftgate is not closed, the picture on the Audio/COMAND display is overlaid with a warning message.
During initial startup, when working on the reversing camera or when working on the trunk lid or the liftgate, the reversing camera has to be calibrated again using the diagnosis tester.
Reversing camera, general
The reversing camera function enables the driver to select between the following parking modes:
- Right angle parking (reverse parking)
- Lengthwise parking (parallel parking)
The corresponding selection takes place at the operating level of the COMAND controller unit. The last selected mode of parking is activated by engaging gear range "R".
In addition, voice assistance can be activated when parallel parking.
The operating instructions for this are described in a separate document.
The reversing camera system includes the following subfunctions:
- Reversing camera function sequence
- Function sequence for activation of outside mirror camera (on model 204.9)
Reversing camera function sequence
The reversing camera function is activated by engaging gear range "R".
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 over the drive train CAN, ME-SFI [ME] control unit and the 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 one another 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 reversing camera control unit over the interior CAN.
The reversing camera control unit then supplies power to the reversing camera.
The pictures recorded by the reversing camera are read in and processed as a CVBS signal by the reversing camera control unit. The reversing camera control unit makes calculations based on the steering angle and the stored vehicle guideline parameters, which are shown on the pictures taken.
The steering angle is recorded by the steering angle sensor. The steering column tube module control unit reads in the signals from the steering angle sensor and sends them to the reversing camera control unit over the chassis CAN, front SAM control unit and interior CAN.
The reversing camera control unit sends the processed pictures as a Composite Video Baseband Signal to the COMAND controller unit. The COMAND controller unit then activates the Audio/COMAND display over the telematics CAN and sends picture data over the LVDS interface. The Audio/COMAND display then shows the pictures recorded by the reversing camera.
Additional function requirements for activating outside mirror camera (with model 204.9)
- Front passenger mirror not folded in
- Passenger door CLOSED
- Vehicle speed v < 15 km/h
Function sequence for activation of outside mirror camera (on model 204.9)
Pressing the corresponding softkeys on the COMAND controller unit activates the front passenger outside mirror camera.
The COMAND controller unit then sends the request over the interior CAN to the reversing camera control unit. The reversing camera control unit activates the front passenger outside mirror camera. The steering angle and stored vehicle parameters are used by the reversing camera control unit to calculate guide lines which are then integrated into the received camera pictures.
The reversing camera control unit then sends these pictures as a CVBS signal to the COMAND controller unit. The COMAND controller unit then activates the Audio/COMAND display over the telematics CAN and sends picture data over the LVDS interface. The Audio/COMAND display then shows the pictures recorded by the reversing camera.
| Electrical function schematic, reversing camera | PE54.65-P-2051-97FAA | ||
| Reversing camera (RFK), operating notes | GF54.65-P-0005-03CEJ | ||
| Overview of system components of parking assistance systems | GF54.00-P-9997CE |