Circuit/System Description
For an overview of the component/system, refer to: Throttle Actuator Control (TAC) System Description
| Circuit | Description |
|---|---|
| 5 V Reference | Regulated voltage supplied by the control module. |
| Serial Data | Digitally encoded information for communication between devices. |
| Low Reference | Grounded through the control module. |
| Component | Description |
|---|---|
| K20 Engine Control Module | The control module contains a microprocessor used to process input data to control outputs. |
| Q38 Throttle Body | The throttle valve is actuated by a DC motor. A spring pulls the throttle valve to the closed position, the throttle actuator motor pushes in the open direction. The more current flows through the motor, the more the valve opens. For a closed loop control, the ECM uses 2 redundant throttle position sensors. |
K20 Engine Control Module
The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.
The engine control module (ECM) determines the driver's intent based on input from the accelerator pedal position sensors, then calculates the appropriate throttle response based on the throttle position sensors.
Q38 Throttle Body
The throttle valve is actuated by a bidirectional DC motor. A spring pulls the valve to a rest or default position, in which the valve is almost closed. The throttle actuator motor can push against the force of the spring to open or close the valve. The more current flow through the motor, the more the valve moves.
The throttle body contains a contactless inductive position sensor. A fixed transmitter coil excites a movable rotor, which in turn induces a current in a fixed receiver coil. The current varies with the angle of the rotor. Electronics inside the sensor convert the current into digital data which is transmitted via a serial data circuit to the ECM.