General information
The car is equipped with ABS BOSCH 8.0 system.
Depending on the vehicle equipment level, the BOSCH 8.0 system includes only ABS brakes or ABS combined with a trajectory stabilization system (SST).
Note. After carrying out any work on the Trajectory Stability System, the results of the repair must be verified by a road test and also with a diagnostic tool (CLIP).
Description of the ABS system with trajectory stabilization function
The ABS system consists of:
- vacuum brake booster assembly with the main brake cylinder;
- electric pump assembly, including a hydraulic pump and a pressure control unit (12 solenoid valves);
- ABS ECU;
- pressure sensor;
- steering wheel angle sensor built into the electric power steering;
- combined sensor of angular and transverse acceleration;
- four wheel speed sensors;
- trajectory stabilization function switch.
The principle of operation of the ABS system with the function of trajectory stabilization
The optimum parameters are calculated continuously based on measurements of wheel speed and steering angle. These parameters reflect the optimal behavior of the car on the road.
They are compared with the real parameters of the car movement based on the measurements of the speed of the angular and lateral accelerations.
When a deviation of the real trajectory from the optimal one is detected, the corresponding wheel is braked. In some cases, with insufficient controllability, the system brakes both wheels at the same time. The moment of forces created in this way returns the car to the optimal trajectory.
In some cases the system (when the anti-slip function is activated) changes the torque of the engine.
Feature of the trajectory stabilization system
The trajectory stabilization system function can be disabled by a switch located on the instrument panel.
The system cannot be disabled if the speed exceeds the threshold value of 50 km/h.
The system automatically reactivates when the ignition is switched on or if the speed exceeds 50 km/h.
Hydroblock
Pic. 6.83. ABS pump control unit
The ABS pump assembly is equipped with a 26-pin ECU (pic. 6.83).
Pic. 6.84. ECU for the electric pump of the trajectory stabilization system and the ABS system
The electric pump assembly of the trajectory stabilization system and the ABS system is equipped with an ECU with a 46-pin connector (pic. 6.84).
Note. The ECU forms one unit with the electric pump assembly.