Blind Spot Monitor, Function - GF54.71-S-4000TRF
Model 447
With Code JA7 (Blind Spot Monitoring)
With Code XM0 (Facelift)
Shown on model 447.8 with engine 654
shown on model 447.6/7 with engine 654
Illustration of the Blind Spot Assist principle
The following information is evaluated by the right rear Blind Spot Assist radar sensor:
- Terminal status 15
- Blind spot assist status
- Engine running or drive train operational.
- Vehicle moving forward
- Vehicle speed
- Gear range engaged (with automatic transmission)
- Brake status
- Status of trailer recognition (With Code Q22 (trailer coupling with non-removable ball head) or With Code Q50 (trailer coupling with removable ball head))
Terminal status 15
The electronic ignition lock control unit sends the terminal status terminal 15 via the front end CAN to the right rear Blind Spot Assist radar sensor.
Blind spot assist status
The instrument cluster (IC) control unit sends the status of the Blind Spot Assist to the right rear Blind Spot Assist radar sensor.
Engine running or drive train operational
The CDI control unit or ME-SFI control unit (N3/34) (with engine 274) sends the "Engine running" or the "Drivetrain ready" signal via chassis CAN, electronic ignition lock control unit (EZS) and front end CAN to the right rear Blind Spot Assist radar sensor.
Vehicle moving forward
Forward movement is defined via the wheel rotation direction. The Electronic Stability Program (ESP) control unit sends the wheel rotation direction to the right rear Blind Spot Assist radar sensor.
Vehicle speed
The vehicle speed is calculated from the wheel speed. The Electronic Stability Program (ESP) control unit sends the vehicle speed to the right rear Blind Spot Assist radar sensor.
The detection ranges of the radar sensor system are based on the angle at which the radar waves are emitted. They are extrapolated by the right rear Blind Spot Assist radar sensor to produce the actual monitoring ranges.
Gear range engaged (with automatic transmission)
The fully integrated transmission control electric controller unit sends information on the engaged drive range to the right rear Blind Spot Assist radar sensor.
Brake status
The status of the brake is sent by the Electronic Stability Program (ESP) control unit to the right rear Blind Spot Assist radar sensor.
Status of trailer recognition (With Code Q22 (trailer coupling with non-removable ball head) or With Code Q50 (trailer coupling with removable ball head))
If a trailer is detected, the trailer recognition control unit sends the "Trailer detected" status to the right rear Blind Spot Assist radar sensor.
The Blind Spot Assist system includes the following subfunctions:
- Measuring procedure function sequence
- Function sequence for system and warning messages
Measuring procedure function sequence
Vehicles are detected based on the radar measuring procedure. The radar sensors send pooled electromagnetic waves as primary signals. If these waves hit an object (vehicle in the blind spot), they are reflected by it and received again by the corresponding Blind Spot Assist radar sensor 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.
The right rear Blind Spot Assist radar sensor reads in the signals from the left rear Blind Spot Assist radar sensor and evaluates them.
Illustration showing rear monitoring range
Function sequence for system and warning messages
When terminal 15 is switched on, the left and right Blind Spot Assist readiness and warning displays light up red until the CDI control unit or ME-SFI control unit sends the "Engine running" or "Drivetrain operational" signal. Additionally, when the "Assistance" menu is switched on in the instrument cluster (IC) control unit, the readiness of the Blind Spot Assist is indicated in the multifunction display of the instrument cluster (IC) control unit (in the multifunction display, gray radar waves appear spreading toward the rear next to the vehicle). If system errors are detected, a corresponding fault message appears instead of the readiness indicator.
The request to issue system and warning messages is sent by the right rear Blind Spot Assist radar sensor to the left or right front door control unit. This then actuates the corresponding Blind Spot Assist readiness and warning display at the left or right.
The right rear Blind Spot Assist radar sensor also transmits the request to output system, fault, and warning messages in the instrument cluster (IC) control unit.
If, at a speed of ≥ 30 km/h, a vehicle is located in the detection range of the radar sensor system, the driver is warned by the left or right Blind Spot Assist readiness and warning display lighting up red on the left or right outside mirror on the side where there is a vehicle in the blind spot. Additionally, a warning is shown in the multifunction display of the instrument cluster (IC) control unit. 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 left or right Blind Spot Assist readiness and warning lamp, the driver still attempts to change lane and indicates this by operating the combination switch (turn signal light active), a double warning tone is additionally issued once by the instrument cluster speaker. The left or right Blind Spot Assist readiness and warning indicator flashes. If the vehicle leaves the detection range of the radar sensor system, the left or right red flashing Blind Spot Assist readiness and warning indicator is switched off.
The steering column tube module control unit reads in the switch position of the combination switch directly, and sends it to the right rear Blind Spot Assist radar sensor.
Blind Spot Assist warning indication (in the outside mirror), shown on left outside mirror
The following table contains the requirements for displaying system readiness and for showing the visual warning messages:
| Operating state | Blind Spot Assist warning indicators in left or right outside mirror "OFF" | Blind Spot Assist readiness indicator in instrument cluster (IC) control unit, function status "ON" | Blind Spot Assist readiness indicator in instrument cluster (IC) control unit, function status "Operational" | Blind Spot Assist warning display in left or right outside mirror lights up red. | Blind Spot Assist warning display in left or right outside mirror flashes red. |
|---|---|---|---|---|---|
| "Terminal 15 OFF" | X | - | - | - | - |
| "Circuit 15 ON" | - | - | - | X | - |
| Engine running or drivetrain operational. | X | - | - | - | |
| Blind Spot Assist activated via instrument cluster (IC) control unit. | - | X | - | - | - |
| Vehicle accelerates, vehicle speed ≥ 30 km/h | X | X | - | - | |
| Vehicle decelerates, vehicle speed ≤ 25 km/h | X | X | - | - | - |
| Trailer detected (with code Q22 (trailer coupling with non-removable ball head) or with code Q50 (trailer coupling with removable ball head)) | X | - | - | - | - |
| Drive range "R" engaged (with automatic transmission) | X | X | - | - | - |
| Vehicle recognized in blind spot | - | - | X | X | - |
| Turn signal light active, vehicle detected in blind spot | - | - | X | - | X |
| Fault detected | X | - | - | - | - |
| Overview of system components for driver assistance systems | GF54.00-S-9998TRF |