Reversing Camera (RFK), Function - GF54.65-P-0005KJ
MODEL 453.0/3/4 with CODE 218 (Rear view camera) except CODE 494 (US version)
MODEL 453.3/4 up to model year 2018 with CODE 218 (Rear view camera) with CODE 494 (US version)
Function requirements, general
- Terminal 30 ON
- Liftgate closed
- Multimedia system ON
- Function of reversing camera enabled via the control menu of the Smart Radio Multimedia Navigator control unit
The reversing camera is supplied with voltage directly by the Smart Radio Multimedia Navigator control unit.
If the liftgate is not closed, the reversing camera is deactivated and the picture shown on the Smart Radio Multimedia Navigator display is overlaid with a warning message.
The center SAM control unit sends information on the status of the liftgate lock (open or closed) via the interior CAN to the audio gateway control unit. This forwards the information via the telematics CAN to the Smart Radio Multimedia Navigator control unit.
During commissioning and after all work on the liftgate or the rear lamp unit carriers, the reversing camera must be recalibrated using the diagnostic tester.
Reversing camera, general
The reversing camera is located inside the emblem in the liftgate of the vehicle.
The reversing camera is an optical parking and maneuvering aid. Its task is to capture the area to the rear of the vehicle. The images taken by the reversing camera are sent as video signals to the Smart Radio Multimedia Navigator control unit and conditioned there. On the basis of the vehicle dimensions, the vehicle speed and the steering angle, dynamic and static guidelines are generated in the Smart Radio Multimedia Navigator control unit and the current path of the vehicle is shown in the integrated display.
The reversing camera function comprises the following subfunctions:
- Function sequence for activating/deactivating reversing camera
- Function sequence for image capture, image processing and image output of reversing camera
Function sequence for activating/deactivating reversing camera
The reversing camera can be activated by engaging gear range "R". The reversing camera is deactivated when a gear range other than "R" is engaged or when the vehicle's engine is switched off.
Automatic activation/deactivation of the reversing camera must be enabled at the corresponding operating level of the Smart Radio Multimedia Navigator control unit.
The engaged gear range is detected by the electronic selector lever module control unit for vehicles with automatic transmission (code 429 (twinamic) and on model 453.091/391/491) or by the backup lamp activation/idle recognition switch for vehicles with manual transmission (code 410 (5-speed manual transmission)). The center SAM control unit receives the signal "Reverse gear engaged", converts it into the reverse gear status signal and sends this via the interior CAN to the audio gateway control unit. This forwards the information via the telematics CAN to the Smart Radio Multimedia Navigator control unit.
The Smart Radio Multimedia Navigator control unit evaluates all the input factors and activated or deactivates the power supply to the reversing camera.
When the power supply is active, the reversing camera sends the video signal for processing and display to the Smart Radio Multimedia Navigator control unit.
The reversing camera is deactivated under the following conditions:
- After deactivation of gear range "R"
- Engine off (except model 453.091/391/491) or drivetrain off (model 453.091/391/491)
Function sequence for image capture, image processing and image output of reversing camera
The image from the reversing camera is displayed in the integrated display of the Smart Radio Multimedia Navigator. The area behind the vehicle is displayed mirror-inverted, as it is in the inside rearview mirror. The navigation menu of the Smart Radio Multimedia Navigator allows the user to make the following settings:
- Reversing camera settings
- Activate and deactivate the reversing camera
- Display and hide the static orientation lines
- Display and hide the dynamic orientation lines
- Picture settings
- Brightness
- Saturation
- Contrast
The display of the Smart Radio Multimedia Navigator automatically adjusts the background illumination to day and night conditions. For this, the instrument cluster sends the status of circuit 58 d via the interior CAN to the audio gateway control unit. The signal is forwarded via the telematics CAN to the Smart Radio Multimedia Navigator control unit for evaluation.
The reversing camera sends a video signal to the Smart Radio Multimedia Navigator control unit. Based on the steering wheel angle and stored vehicle parameters (lane and exterior contour of the vehicle), the Smart Radio Multimedia Navigator control unit calculates the static and dynamic orientation lines and overlays them on the image from the reversing camera in the display of the Smart Radio Multimedia Navigator.
The steering wheel angle is registered by the steering wheel angle sensor. This sends the steering wheel angle sensor signal via the chassis CAN to the Electronic Stability Program control unit. This relays the signal via the interior CAN to the audio gateway control unit. The audio gateway control unit forwards the steering wheel angle sensor signal via the telematics CAN to the Smart Radio Multimedia Navigator control unit.
Virtual steering angle (dynamic orientation lines)
As soon as the driver turns the steering wheel, the dynamic orientation lines (2) are displayed in blue. They indicate to the driver the path which the vehicle would follow with the current steering wheel angle. This curve is automatically adapted as the steering wheel angle changes. The distance between the dynamic orientation lines (2) represents the vehicle width across the outside mirrors.
Parking procedure
In order to achieve the optimum angle for the parking process, the driver must adjust the steering wheel angle until an outer line of the blue dynamic orientation lines (2) touches the parking space marking in the display. This parking space marking may be e.g. another vehicle or the line on the asphalt. The driver must continue reversing and adjusting the steering angle until the displayed parking space limits run parallel to the current direction of travel.
Virtual vehicle width (static orientation lines)
Next, the driver must turn the steering wheel back into the straight-ahead position in order to drive in a straight line up to the final park position in the parking space. While doing so, the driver can check - using the static orientation lines (1) - whether the vehicle is in a straight position relative to the parking space, and whether the parking space is wide enough. The static orientation lines are also subdivided into colored segments, indicating different distances between the rear end of the vehicle and potential obstacles. The red zone up to the 0.3 m distance lines (c) represents a distance of less than 0.3 m to the vehicle. The yellow zone up to the 0.7 m distance lines (b) represents a range from 0.3 m to 0.7 m and the green zone up to the 1.5 m distance lines (a) represents a range from 0.7 m to 1.5 m.
The distances apply only for objects at ground level.
The reversing camera may show obstacles with distorted perspective, incorrectly or not at all. Obstacles in the following locations are not displayed by the reversing camera:
- Very close to the rear bumper
- Underneath the rear bumper
- Close to and above the handle recess of the liftgate
Functioning of the reversing camera may be limited when
- It is raining heavily, snowing or foggy
- The camera lens is iced up (magnifying effect)
- It is night or the vehicle is in a very dark location
- The camera is exposed to very strong, bright light
- The surroundings are illuminated with fluorescent light, e.g. from fluorescent lamps or LEDs (the display may flicker)
- Rapid temperature changes occur, e.g. in winter when driving in from the cold into a heated garage
- The camera lens is dirty or obscured
- The rear of the vehicle is damaged
Additional vehicle attachments mounted at the rear, e.g. license plate bracket or bicycle carrier, may also restrict the viewing range and other functions of the reversing camera.
Display limits of the dynamic orientation lines
The dynamic orientation lines may be displayed incorrectly or be absent altogether because at vehicle speeds below 12 km/h the Electronic Stability Program control unit returns relative measurements instead of absolute measurements.
If the steering wheel is turned by more than 30° in one direction with the engine off (except model 453.091/391/491) or drivetrain off (model 453.091/391/491) and then the engine or drivetrain is started, the dynamic orientation lines (2) are not displayed.
If the steering wheel is turned through one or more complete turns with the engine off (except model 453.091/391/491) or drivetrain off (model 453.091/391/491) and then left in the original position (+/-30°), then the dynamic orientation lines (2) are displayed with an erroneous angle.
In both case, the correct display is restored when the vehicle reaches a speed of at least 6 km/h.
| Electrical function schematic, reversing camera | PE54.65-P-2051-97BBA | ||
| Overview of system components of parking assistance systems | GF54.00-P-9997KJ |