PRINCIPLE OF OPERATION
EPS controls servo assistance for steering. In addition to the measuring the driver's steering torque, the EPS Control Module also monitors further inputs such as
- Vehicle Speed
- Dynamic Driving Control (Sport) Button
- Steering Angle Velocity
- Internal System Temperature
- Steering Angle
The EPS calculates an assistance set point. The electric motor is activated via the integrated power electronics and the torque is transmitted through the worm gear to the driven gear (attached to the steering column output shaft). The Servotronic function (vehicle speed dependent steering assistance) is also integrated. The corresponding assistance and damping characteristics are stored in the EPS Control Module. The required assistance torque is gradually increased when the engine is started and reduced (with a delay) when the engine is switched off.
GENERAL INFORMATION
The mass balance spring (arrow) should be disconnected when work is performed on the upper steering column. Use caution as the mass balance spring is under extreme tension. Be careful not to bend the spring tab mounting retainers. Only the ignition starter switch, the lock cylinder and the Steering Angle Sensor (LWS) can be replaced as separate components on the upper steering column. see scheme 9
