System Overview

Block Diagram:

DESCRIPTION
The Electronic Throttle Control (EML) system replaces the previous mechanical transmission and transfer linkage of the accelerator pedal angle between the accelerator pedal and throttle valve.

The most important components of EML are the control unit, Pedal Value Sender (PWG) and the EML Throttle Valve (DK).

In addition to transmission of the accelerator pedal angle (position) from the accelerator pedal to the throttle valve. the EML system performs several other functions.

- Idle speed control

- Engine speed limitation

- Vehicle speed control (Cruise Control FGR)

- Throttle valve opening in accordance with various characteristic progression curves which are selected from a pedal characteristic map corresponding to the drive status

- Interfaces for data exchange with other control units (e.g. Automatic Stability Control (ASC), Digital Motor Electronic (DME) and Electronic Transmission Control (EGS)

- Safety test of important components used by the EML system - Maintaining vehicle operability in the event of component failure by making available substitute values

- Self-Diagnosis

All functions are monitored by the control unit program. This monitoring function also includes the program run of the control unit. The program run is controlled by the hardware. When the hardware detects a defect, the program run is terminated and then restarted.