Contents: Idle mode control ⇊ Acceleration control ⇊ Cruise control system ⇊ Accelerator Pedal Position Sensor…⇊ Throttle body ⇊ Idle speed control system ⇊ Brake pedal position sensor ⇊ Electric Power Steering (EPS) Signal…⇊ Electronic throttle control system…⇊
The throttle valve is electronically controlled by the electronic throttle position control system. See the system diagram for a functional diagram of this system.
Idle mode control
When the engine is idling, the ECM computer controls the throttle rotation actuator in order to maintain the required idle speed under any engine load.
Acceleration control
When the accelerator pedal is pressed, the ECM opens the throttle valve depending on the signal from the accelerator pedal position (APP) sensor.
Cruise control system
When the cruise control system is operating, the ECM computer controls the operation of the throttle rotation actuator in order to maintain the set speed. The throttle rotation actuator acts as an actuator of the cruise control system.
Accelerator Pedal Position Sensor (APP)
As the accelerator pedal position changes, the sensor changes the voltage signal sent to the ECM.
Throttle body
The throttle body is single-chamber with a side-mounted throttle actuator. The lower area under the throttle valve is heated by engine coolant supplied from the cylinder head to prevent ice from forming on the throttle valve.
Idle speed control system
When the engine is cold, the air conditioner is on, the transmission is in gear, the brake pedal is depressed, there is a high power steering load, or there is a high generator load, the ECM controls the current supplied to the throttle actuator to maintain the desired idle speed.
Brake pedal position sensor
The brake pedal position sensor sends a signal to the ECM when the brake pedal is pressed.
Electric Power Steering (EPS) Signal (versions with EPS hydraulic booster)
The EPS system sends a signal to the ECM when the load on the power steering is too high.
Electronic throttle control system diagram
The electronic throttle control system consists of a throttle actuator, a throttle position (TP) A/B sensor, an accelerator pedal position (APP) sensor, an electronic throttle control system (ETCS) relay, and an ECM.