EML Throttle Valve (DK)

OPERATION
By way of a servomotor (actuator), the EML throttle valve (DK) is opened by the output stage in the EML control unit against the force of a spring. The output stage activates the servomotor with square-wave voltage which has a fixed frequency. The different settings of the EML throttle valve are achieved by altering the ratio between the cut-in and cut-out duration.

When the EML control unit or the EML throttle valve are renewed, or power is cut to the control unit, the information relating to the lower throttle valve (DK) limit stop is lost or incorrect. The EML control unit therefore has a teaching feature which learns the throttle valve (DK) limit stop position once again. When learning this throttle valve (DK) limit stop, the EML system establishes the relationship between the mechanical limit stop and the throttle valve (DK) potentiometer angle. The learning procedure assumes that the vehicle is in cruising mode, the detected water temperature is > 60° C and the engine speed is> 1920 rpm. When all these conditions are fulfilled, the servomotor (actuator) slowly moves the throttle valve against the lower mechanical limit stop. When this limit stop is reached, the EML system stores this teaching value. This learning procedure is carried out during each vehicle start until the new value can be stored.