Throttle valve actuator, basic function

P07.61-A005-79

P07.61-A003-79

Overview

This document contains information on:

 General

 Location

 Function

General

The throttle valve actuator regulates the following functions:

 Exhaust gas recirculation

 Idling speed

 Driving mode (according to accelerator pedal position and engine load)

 Cruise control function

 Electronic accelerator pedal emergency running mode, function

In a deenergized state (e.g limp-home mode), the opening angle of the throttle valve is determined by the return spring (limp-home position).

The throttle valve actuator checks its return spring at "Ignition ON" under the following preconditions:

 Gear range "P" or "N" engaged

 Vehicle at rest

 Engine "OFF"

 Coolant temperature between 5 and 100 °C

 Accelerator not operated

The combustion engine control unit automatically adapts the throttle valve actuator the first time that the throttle valve actuator is connected to the vehicle.

Location

The throttle valve actuator is located upstream of the intake manifold in the intake air system.

Function

The throttle valve actuator motor continuously adjusts the opening angle of the throttle valve from approx. 0 to 90° according to the presets from the combustion engine control unit.

In doing so, both counter-moving actual value potentiometers 1 and 2 inform the combustion engine control unit of the throttle valve’s current position.

The adaptation is performed within about 60 s after first energization (ignition ON) and comprises:

 Identified limp-home position

 Identified lower mechanical end stop of throttle valve

 Adaptation of actual value amplifier (signals 1 and 2) in combustion engine control unit

 Checking the return spring

P07.70-A028-71