Component description for the throttle valve actuator - GF30.20-P-2020AMG

ENGINE 156.980 in MODEL 164, 251 up to Model Year 8

ENGINE 156.982 in MODEL 209

ENGINE 156.983 in MODEL 211, 219

ENGINE 156.984 in MODEL 216, 221 up to Model Year 8

Location

Fig 1: Locating Throttle Valve Actuators

Courtesy of MERCEDES-BENZ USA

The throttle valve actuator is located under housing bottom section in the variable intake manifold.

Task

The throttle valve actuator regulates the functions:

Idle speed
Driving mode (according to accelerator pedal position and engine load)
Cruise control mode
Electronic accelerator emergency mode

Function

Actuator motors (M16/3m1, M16/4m1) in the throttle valve actuator adjust the opening angle of the throttle valve continuously from about 0 to 90° according to specifications from the ME-SFI [ME] control unit (N3/10). Both throttle valves are always actuated at the same time (same opening angle for both throttle valves).

The ME-SFI [ME] control unit is informed about the current positions of the throttle valves by two actual value potentiometers respectively operating in the opposite direction. In idle the signal from actual value potentiometer sliding contact 1 (M16/3r3, M16/4r3) is at about 0.5 V and the signal from actual value potentiometer sliding contact 2 (M16/3r4, M16/4r4) is at about 5 V. In a deenergized state, the opening angle of the throttle valve (from 4°) is determined by a spring capsule (limp-home position).

For "ignition ON" the ME-SFI [ME] control unit is always checking the limp-home position of the throttle valves. Prerequisites for checking the limp-home position are:

Ignition ON
Drive position P or N
Vehicle at rest
Engine OFF
Coolant temperature 5 to 100°C
Accelerator not operated

For first time connection of a throttle valve actuator to the vehicle the ME-SFI [ME] control unit automatically execution adaptation of the actuator. These include:

Determining the limp-home position of the throttle valve
Determining the lower mechanical stop of the throttle valve
Adaptation of the actual value amplifier (from signal 1 and 2) in the ME-SFI [ME] control unit