Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Collision Warning System Controller Unit, Basic Function - GF30.30-P-9893A
Model all (CAR)
Task
The Active Brake Assist controller unit detects obstacles in front of the vehicle and warns the driver about possible collisions. The Active Brake Assist controller unit differentiates, in this connection, between vehicles in front, crossing traffic and bike riders. If the Active Brake Assist controller unit detects a collision risk, it initiates an autonomous brake application.
The Active Brake Assist controller unit is connected to the network architecture of the vehicle.
For the implementation of the functions, the Active Brake Assist controller unit processes among other things the following information:
- Terminal status of terminal 15
- Operating condition for engine/drivetrain
- Wheel speed and wheel rotation direction
- Acceleration/yaw rate
- Electronic Stability Program (ESP®) status
- Steering wheel angle and steering wheel velocity
- Accelerator pedal position
- Brake pedal position
- Driver's requests via menu settings
Depending on the national version, the Active Brake Assist controller unit also processes object information of the multifunction camera behind the windshield.
The Active Brake Assist controller unit processes this information and transmits among other things the following requests:
- Warning output requests
- Requirements for initiating PRE-SAFE® measures
- Increase braking torque request
- Request to reduce engine torque
Structure
The Active Brake Assistant controller unit contains the following assembly parts:
- Radar sensor
- Control unit
Properties of the radar sensor:
- Detection range:
- 40 m for a detection angle of 45°
- 160 m for a detection angle of 7.5°
- Detection range (from FAP5/introduction of model series 223):
- 70 m for a detection angle of 45°
- 250 m for a detection angle of 9°
- Operating frequency: 77 GHz
The radar sensor works according to the Pulse-Doppler principle for the independent measurement of distance and speed.
The Active Brake Assistant controller unit must be newly adjusted after exchange (e.g. after an accident repair) using the integrated "service adjustment mode".
| Detailed information | |||
| Collision warning system controller unit, detailed information | Model 118, 177, 247 | GF30.30-P-9893-01A | |
| Model 167, 293 | GF30.30-P-9893-01B | ||
| Component descriptions | |||
| Active Brake Assist controller unit, component description | Model 243 with code 258 (Active Brake Assist System) |
GF30.30-P-3222B | |
| Collision warning system radar sensor, component description | Model 223 | GF30.30-P-3311A | |
| Model 206 | GF30.30-P-3311C | ||
| Model 297 | GF30.30-P-3311D | ||
| Model 295 | GF30.30-P-3311E |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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