Dynamic Stability System — Basic Information and Component Replacement (BMW 3 Series E46)

Basic information

1. The Dynamic Stability Control (DSC) system is fitted to all models with 6-cylinder engines and is optional on all other models. This system combines the functions of the ABS and traction control systems. This section describes the Cornering Brake Control (CBC) part of the system. This system monitors wheel speed, wheel load, vehicle speed, lateral acceleration and controls the pressure in all four wheel brake cylinders during braking, reducing the risk of skidding when turning.

Replacement of components

Angle sensor

2. Replacing this sensor requires complete disassembly of the steering column, so it is better to entrust this work to specialists at a service station. Note: After replacing the sensor, it must be calibrated, which requires special equipment. This procedure can only be performed at a specialized service station.

Front Suspension Ground Clearance Sensor

3. Unscrew the nut securing the rod to the sensor lever (see Fig. 12.3 in Chapter 12.).

4. Remove the two screws and remove the sensor. After removing the sensor, disconnect the electrical connector from it.

5. Install the sensor in the reverse order. After finishing the work, adjust the headlight control system.

Control unit

6. The stability control unit is part of the ABS control unit. Replacement of this unit is performed by a BMW dealer (see paragraph 20 of chapter 9).

Booster pump

Note: After replacing the booster pump, it is necessary to bleed the high-pressure circuit of the brake system. To do this, contact a specialized service station.

7. The booster pump is located under the master cylinder. Clamp the hose from the master cylinder reservoir to the pump, then disconnect the hose from the pump. Be prepared for fluid leakage.

8. Unscrew the fitting nut and disconnect the pipeline from the pump.

9. Disconnect the electrical connector from the pump and remove the pump from the rubber support.

10. Installation is performed in the reverse order of removal. Bleed the brake system (see chapter 9).

Lateral acceleration sensor

11. Remove the driver's seat (see chapter 11).

12. After removing the seat, lift the floor panel and slide the insulation forward approximately 10 cm to access the sensor.

13. Remove the four screws securing the sensor bracket to the body, first lift the inner end of the sensor and remove it (fig. 27.13). After removing the sensor, disconnect the electrical connector from it.

Note: The sensor is very sensitive to impact. Please handle it with care.

14. If necessary, remove the two screws and detach the sensor from the bracket.

15. Installation is performed in the reverse order of removal. When installing, tighten all fasteners to the required torque.