ESP System Sensors and Components, Description
Control module for ABS with EDL/ASR/ESP -J104
The control module is combined with the hydraulic unit as one unit. It controls the ESP, ABS, EDL, ASR, EBD and ETR (Engine Torque Reduction) functions. When ignition is switched on, the control module performs a self-test. All electrical connections are monitored constantly and the solenoid valves are periodically checked for function. If the control module fails entirely, only the normal brake system will be available.
Steering angle sensor-G85
The steering angle sensor is housed together with the airbag spiral spring/return spring with slip ring. It is located on the steering column between the steering column switch and steering wheel. It transmits the steering wheel's steering angle to the ABS control module -J104 for ABS/ASR/ESP via the CAN-bus. After replacing the control module or the sensor, a zeroing must be performed. For malfunctioning sensor, the ESP function is not available.
Sensor for transverse acceleration -G200
The sensor for transverse acceleration transmits the values of lateral acceleration (cornering force) to the ABS control module -J104 for ABS/ASR/ESP. After replacing the control module or the sensor, a zeroing must be performed. For malfunctioning sensor, the ESP function is not available.
Sender for rotation rate -G202
The sender for rotation rate collects data, so called yaw moments or rotation rates, that attempt to spin the vehicle on the vertical axis and it sends these to control module -J104- for ABS/ASR/ESP. For malfunctioning sensor, the ESP function is not available.
Sender 1 for brake booster-G201
The brake pedal position sensor recognizes the current brake pressure in the brake circuit and sends this data to the ABS control module (w/EDL) -J 104-. From this, the control module calculates the wheel braking powers and therefore the vertical forces affecting the vehicle. If the sensor fails, the ESP function is not available.
ASR/ESP button -E256
The button enables the driver to switch off the ESP function. By operating the brake pedal or by pressing the button again, it is switched back on. If re-activation is forgotten, the system automatically reactivates itself once the vehicle is restarted. The system cannot be switched off when ESP is actively engaged and above a specific speed.
Brake recognition switch (ESP)-F83
The brake recognition switch (ESP) is also identified as a release switch and it functions like a pole-changing switch. When the driver brakes, the switch changes from signal terminal 1 to signal terminal 2. Since only one signal terminal is ever closed, the system easily recognizes the current condition and the release switch thereby offers a high degree of personal safety.
Hydraulic pump for traction control -V156
In order to generate the required admission pressure on the intake side of the return flow pump, an additional hydraulic pump is necessary. Boost pressure is limited via a throttle in the main cylinder, the hydraulic pump for traction control -V156- itself is not regulated.
Examples:
During oversteering, the rear of the vehicle breaks out toward the outside of the curve. The vehicle rotates more on its vertical axis than required to maneuver through the curve. Braking the outside front wheel counters the oversteering effect.
In understeering, it is the front of the vehicle that does not follow the curve. The front of the vehicle breaks out. The vehicle rotates less on its vertical axis than is required to maneuver through the curve. By braking the rear inside wheel, the braking force generated intensifies the rotational movement of the vehicle.
Component locations (except for new components) are the same as for the Bosch 5.3 components. The procedures for removal and installation of the components are found in: