Throttle Actuator
Throttle Actuator
Throttle actuator
The electromotive throttle actuator is secured to the intake plenum. The DME control unit calculates the position of the throttle valve from:
- Accelerator pedal module setting
- Torque request from other control units
The DME control unit opens and closes the electromotive throttle actuator electrically.
Functional description
The throttle valve opening angle in the electromotive throttle actuator is monitored by 2 hall effect sensors. The throttle valve is moved by an electric actuator motor. This actuator motor is actuated by a pulse width modulated signal with a basic frequency of 1000 Hz.
The throttle valve has a mechanical adjusting range of 0 to 90°. The maximum position that is actually moved to is 81° (corresponds to 100 % throttle valve opening).
In the de-energized state, the throttle valve is held in the emergency running position of approx. 5.2° by 2 throttle return springs. These two springs also ensure that the throttle valve is returned to this position in the event of a fault (actuation deactivated).
The DME converts the required throttle opening setpoint value into an actuation command using the measured actual position.
The diagnosis monitors both hall effect sensors for electrical functionality (short circuit to ground, short circuit to B+ and line disconnection) and for the plausibility of the sensor signal.
The diagnosis runs continuously as soon as the following preconditions are satisfied:
- Terminal 15 on
- No electrical fault detected
Structure and inner electrical connection
The hall effect sensors are non-contact sensors. For safety reasons, the hall effect sensors supply an opposing signal (redundancy). The second sensor supplies the mirrored voltage values at all operating points.
Signal shape and setpoint values
The engine control unit receives a measured value between 0 and 5 volts from the hall effect sensor. With the aid of the taught-in bottom limit position and an encodable slope, the DME converts this voltage into the throttle valve opening angle. The diagnosis monitors the two signals for an upper and lower voltage limit.
Observe the following setpoint values for the electromotive throttle actuator:
Size Value
Servomotor supply voltage 9 to 17 volts
Servomotor frequency range 400 to 16000 Hz
Supply voltage, hall effect sensors 4.5 to 5.5 V
Hall effect sensor signal voltage 0 to 5 volts
Hall effect sensor power 10 mA
consumption
Temperature range for hall effect -40 °C to 140 °C
sensors and servomotor
Diagnosis instructions
Failure of the component
If a hall effect sensor fails, the following behavior is to be expected:
- Fault entry in the engine control unit
- Emergency operation with substitute value (limited engine torque)
- Check Control message
If the servomotor fails, the following behavior is to be expected:
- Fault entry in the engine control unit
- The throttle-valve assumes its mechanical emergency-air position
- Check Control message
We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.