Blind Spot Assist, Function - GF54.71-P-0003RR
Model 190
With Code 22P (Lane tracking package)
Shown up to 30.11.2018
Shown as of 01.12.2018
Function requirements, general
- No undervoltage or overvoltage
- Blind Spot Assist activated
- Engine running or drive train operational
- Vehicle moving forward
- Vehicle speed of approx. 30 km/h
Blind Spot Assist, general
The Blind Spot Assist monitors the rear and side areas of the vehicle using short range radar and, if necessary, informs the driver that an intentional lane change (turn signal light active) is not recommended at this time. In a broader sense, Blind Spot Assist acts as an extension of the inside rear-view mirror. It does not release the driver of his/her obligation to perform lane changes safely on his/her own responsibility.
In the respective outside mirror, a visual indicator indicates the status of Blind Spot Assist and warns of critical situations during a lane change (i.e. a vehicle is in the "blind spot"). A warning tone can also be issued.
The visual warning is issued via the Blind Spot Assist warning lamp in the respective outside mirror.
The acoustic warning is output over the instrument cluster speaker.
The area which cannot be observed via the outside mirror and inside rear-view mirror is monitored by the following components:
- Right outer rear bumper integrated radar sensor
- Left outer rear bumper integrated radar sensor
All relevant data is evaluated by the integrated rear bumper radar sensors, whereby the right rear bumper radar sensor requests the warning output.
The integrated rear bumper radar sensors operate according to the "Masterslave" principle. The master or slave function can be determined via the connector coding. The master function is defined for the integrated right rear bumper radar sensor. In other words, the integrated left rear bumper radar sensor sends its information via chassis CAN 1 to the integrated right rear bumper radar sensor which then evaluates the corresponding information from both integrated rear bumper radar sensors and sends corresponding requests or data via chassis CAN 1 to the corresponding control units.
Illustration of the Blind Spot Assist principle
The following information is evaluated by the rear bumper radar sensors:
- Terminal status of terminal 15
- Blind spot assist status
- Engine running or drive train operational
- Vehicle moving forward
- Vehicle speed
Status of circuit 15:
The electronic ignition lock control unit sends the circuit status of circuit 15 via chassis CAN 1 to the integrated rear bumper radar sensors.
Blind Spot Assist status:
Up to 30.11.2018
The instrument cluster sends the status of the Blind Spot Assist to the integrated rear bumper radar sensors via the user interface CAN, the AMG gateway control unit, chassis CAN 2, the front SAM control unit and chassis CAN 1.
As of 01.12.2018
The status of the Blind Spot Assist is sent by the head unit over the user interface CAN, AMG gateway control unit and suspension CAN 1 to the integrated rear bumper radar sensors.
Engine running or drive train operational:
The ME-SFI control unit sends the "engine running" or "drivetrain operational" signal via the drive train CAN, the powertrain control unit and chassis CAN 1 to the integrated rear bumper radar sensors.
Vehicle moving forward:
Forward movement is defined via the wheel rotation direction. The Electronic Stability Program control unit sends the information about the wheel rotation direction via chassis CAN 1 to the integrated rear bumper radar sensors.
Vehicle speed:
The vehicle speed is calculated on the basis of the wheel speeds. The Electronic Stability Program control unit sends the information about the wheel speed via chassis CAN 1 to the integrated rear bumper radar sensors.
The Blind Spot Assist function consists of the following subfunctions:
- Measuring method
- System and warning messages
Measuring method
Objects (vehicle in blind spot) are detected using the radar measuring procedure. The radar sensors integrated in the rear bumper emit bundled electromagnetic waves as "primary signals". If these waves hit an object, they are reflected by it and are received again by the corresponding radar sensor integrated in the rear bumper as a secondary signal. These signals are used to calculate the distance and the speed of the detected object as well as its angle relative to the vehicle.
Detection area of the radar sensor system
The integrated rear bumper radar sensors detection range is based on the angles of the radar waves. These are extrapolated by the respective integrated rear bumper radar sensor to produce the actual monitoring ranges.
Illustration showing actual rear monitoring range
System and warning messages
When circuit 15 is switched on the Blind Spot Assist warning lamps light up for 1.5 s in red and then yellow (readiness display). As from a vehicle speed of roughly 30 km/h the Blind Spot Assist warning lamps go off again and the Blind Spot Assist is operational.
If a system error is detected, a corresponding message is shown in the instrument cluster and the Blind Spot Assist warning lamps light up yellow.
Up to 30.11.2018
The integrated right outer rear bumper radar sensor sends the function readiness status and/or the request to output fault messages via chassis CAN 1, the front SAM control unit, chassis CAN 2, the AMG gateway control unit and the user interface CAN to the instrument cluster (output of fault messages) and via chassis CAN 1, the front SAM control unit and the interior CAN to the respective door control unit, which then actuates the corresponding Blind Spot Assist warning lamp.
As of 01.12.2018
The function readiness status or the request to issue fault messages is sent by the integrated rear outer right bumper radar sensor over suspension CAN 1, the AMG gateway control unit and the user interface CAN to the instrument cluster (fault messages output) and over suspension CAN 1, front SAM control unit and the interior CAN to the respective door control unit, which then actuates the corresponding Blind Spot Assist warning lamp.
Blind Spot Assist readiness indicator; illustration shows left outside mirror
If, at a speed of roughly 30 km/h, a vehicle is located in the detection range of the radar sensor system, the driver is warned by the Blind Spot Assist warning lamp lighting up in red in the outside mirror on the side of the vehicle on which the vehicle is in the blind spot. Regardless of their speed differential to the vehicle, passing vehicles are recognized and a warning is issued with Blind Spot Assist. Due to the short reaction time when the difference in speed is high, the warning message output sometimes does not have any added value. If, despite illumination of the Blind Spot Assist warning lamp, the driver still attempts to change lane and indicates this by operating the combination switch (operates turn signal light), a double-warning tone is also issued by the instrument cluster speaker.
Up to 30.11.2018
The integrated right outer rear bumper radar sensor sends the request to output an acoustic warning via chassis CAN 1, the front SAM control unit, chassis CAN 2, the AMG gateway control unit and the user interface CAN to the instrument cluster.
As of 01.12.2018
The integrated rear right outer bumper radar sensor sends the request to issue a warning tone over suspension CAN 1, AMG gateway control unit and user interface CAN to the instrument cluster.
The instrument cluster then actuates the instrument cluster speaker directly.
The Blind Spot Assist warning lamp flashes red. If the vehicle leaves the acquisition range of the radar sensor system, the red flashing Blind Spot Assist warning lamp is switched off.
The signal curve for issuing warnings corresponds to the signal curve for displaying functional readiness.
Up to 30.11.2018
The steering column tube module control unit reads in the switch position of the combination switch directly and sends it via chassis CAN 1 to the integrated rear bumper radar sensors.
As of 01.12.2018
The steering column tube module control unit reads in the switch position for the combination switch directly and sends this over the AMG FlexRay, AMG gateway control unit and suspension CAN 1 to the integrated rear bumper radar sensors.
Blind Spot Assist warning indicator, shown on left outside mirror
The requirements for displaying functional readiness and for issuing visual warning messages are available in the following table:
| Operating state | Warning lamp for Blind Spot Assist OFF | Warning lamp for Blind Spot Assist lights up yellow | Warning lamp of Blind Spot Assist lights up red | Warning lamp for Blind Spot Assist flashes red |
|---|---|---|---|---|
| Circuit 15 OFF | x | - | - | - |
| Circuit 15 ON (t < 1.5 s) | - | - | x | - |
| Circuit 15 ON (t > 1.5 s) | - | x | - | - |
| Engine running or drive train operational | - | x | - | - |
| Vehicle accelerates, vehicle speed v ≥ 30 km/h | x | - | - | - |
| Vehicle decelerates, vehicle speed v ≤ 25 km/h | - | x | - | - |
| Drive position "R" engaged | x | - | - | - |
| Vehicle recognized in blind spot | - | - | x | - |
| Turn signal light active, vehicle detected in blind spot | - | - | - | x |
| Fault detected | - | x | - | - |
Gear range "R" is engaged by the dual clutch transmission control unit. The dual clutch transmission control unit then sends the "gear range R engaged" status to the front SAM control unit via the drive train CAN, the powertrain control unit and chassis CAN 1. The front SAM control unit generates the "reverse gear engaged" status and sends it via chassis CAN 1 to the integrated rear bumper radar sensors.
| Electrical function schematic, blind spot assistant | Model 190 up to 11/30/18 with code 22P (Lane tracking package) | PE54.71-P-2051-97HBA | |
| Model 190 as of 12/1/18 with code 22P (Lane tracking package) | PE54.71-P-2051-97HBB | ||
| Overview of system components for driver assistance systems | GF54.00-P-9998RR |