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 Prevention Assist Controller Unit, Component Description - GF30.30-P-3214LF
Model 217, 222
up to model year 2018
with code 258 (COLLISION PREVENTION ASSIST)
Shown on model 222
Location
The COLLISION PREVENTION ASSIST controller unit is located in the direction of travel at the rear right to the front bumper.
Tasks
The COLLISION PREVENTION ASSIST controller unit detects obstacles and vehicles ahead and warns the driver about a possible collision.
If the COLLISION PREVENTION ASSIST controller unit detects a risk of collision, it initiates autonomous brake application.
This results in the following tasks for the COLLISION PREVENTION ASSIST controller unit:
- Reading in input factors
- Evaluation of input factors
- Transmission of initial parameters
Reading in input factors
The COLLISION PREVENTION ASSIST controller unit receives the following input factors via periphery CAN (CAN PER), among other things:
- Wheel speeds and wheel rotation direction
- Acceleration/yaw rate
- Steering wheel angle
- Accelerator pedal position
- Brake pedal position
- Switch position of combination switch (S4)
- Driver request via menu settings in the instrument cluster (A1)
The resulting functions are described in the respective function descriptions (see also block diagram or function schematic).
Evaluation of input factors
The input factors are evaluated by the microprocessor and the corresponding assembly parts are actuated.
Transmission of initial parameters
The COLLISION PREVENTION ASSIST controller unit transmits the following initial parameters via the periphery CAN:
- Requests to output optical and acoustic warning messages in instrument cluster
- Requirements for initiating PRE-SAFE measures
- Request to increase the braking torque
- Request for torque reduction
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
Structure
The COLLISION PREVENTION ASSIST controller unit includes the following assembly parts:
- Radar sensor
- Control unit
Properties of the radar sensor:
- Detection angle of radar sensor: s = 0 up to 80 m with a detection angle of ∠ = 30° ± 8°
- 25 GHz radar sensor according to the Pulse Doppler Principle for the independent measurement of distance and speed
The COLLISION PREVENTION ASSIST controller unit must be newly adjusted after replacement (e.g. after an accident repair) using the integrated "Service Adjustment Mode".
| Wiring diagram for collision warning system control unit | Engine 157, 276, 277, 278, 279, 642.8, 651 in model 222 up to model year 2018 with code 258 (COLLISION PREVENTION ASSIST) Control unit A90 Engine 157, 278, 279 in model 217 up to model year 2018 with code 258 (COLLISION PREVENTION ASSIST) Control unit A90 |
PE30.30-P-2104-97SEA |
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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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