lemon-mirror:
Home >> Mercedes Benz >> 2000 >> C230 >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Anti-Lock/Traction Control - TEVES >> Description & Operation >> Esp Control Module Function >> Function Logic Component

Function Logic Component

The conditioned input signals are processed in the logic component and converted into output signals.

Signals from wheel speed sensors: The 4 conditioned wheel speed signals are constantly compared with each other and with specified slip thresholds on the front and rear wheels in relation to the speed of the vehicle. This comparison is used to determine the following values and control variables:

If the vehicle changes direction or is being driven on a curve, this is detected using the signal from the steering angle sensor and on the basis of the different rotational speeds of the front wheels. These two variables in conjunction with the ground speed informs the ESP control module of the vehicle handling characteristics desired by the driver.

Signal from lateral acceleration sensor: The ESP control module uses the signal from the lateral acceleration sensor to determine the lateral forces occurring during cornering. The status controller in the ESP control module can detect whether the vehicle is oversteering from the lateral acceleration signal together with the yaw rate signal.

Signal from yaw rate sensor: The ESP control module uses the yaw rate sensor to detect the movements (yaw rate) that the vehicle attempts to make about the vertical axis (e.g., when the vehicle is accelerated). Using the signals from the lateral acceleration sensor and yaw rate sensor, the ESP control module determines the actual handling characteristics of the vehicle.

CAN data on engine torque: The ESP control module is informed about the engine torque output by the engine control module via the CAN data bus. In the case of the ESP control mode, the function logic component tells the engine control unit to set a reduced engine torque.

CAN data on currently engaged gear (automatic transmission only): The function logic component (ESP) is constantly informed about the currently engaged gear by the ETC control module via the CAN data bus. The current gear is used to calculate the drive forces acting on the drive wheels and for drive torque control.

Signal from brake pressure sensor (B34): Model 202 with engine 111: The brake pressure sensor(s) detect(s) the brake pressure which is used by the logic component to calculate the wheel brake forces (longitudinal forces). If ESP control becomes necessary, the existing wheel-brake forces (longitudinal forces) are taken into consideration when the cornering forces (lateral forces) are calculated.

Signal from stop lamp switch (S9/1): When the brake is actuated, signals from the dual contact switch (NO and NC contact) are registered and evaluated by the ESP logic component. This process is terminated immediately if, for example, ASR control becomes active. In the case of ESP control, these information signals are processed in addition to the signal from the brake pressure sensor.

Signal from parking brake switch (S12): If a signal is issued from the parking brake switch, EBR control mode is not permitted.

Signal from ESP OFF switch (S76/6): If a signal is received from the ESP OFF switch, the drive torque control circuit is deactivated and the ESP warning lamp is actuated to shine constantly.

Signal from BAS release switch: When the BAS release switch is not actuated and the BAS solenoid valve is active at the same time, the stop lamps are prevented from lighting when the brake pedal is not depressed. This is effected by actuation of the stop lamp suppression relay or directly by the control module (model 203, 215, 220).

Signal from BAS diaphragm sensor: The signal from the BAS diaphragm travel sensor is used to calculate the speed at which the brake pedal is actuated. The brake pedal speed is used as a criterion for BAS actuation.

· About lemon-mirror