3AE3 MT 2 - Electronic Throttle Control System

PRIORITY: What are the main components of electronic throttle control (ETC)?

Accelerator pedal position (APP) sensor, PCM/control unit, electronic throttle actuator and throttle position (TP) sensor.

PRIORITY: Explain ETC operation in order.

The APP sensor reports pedal position → PCM determines the required throttle opening → actuator moves the throttle plate → TP sensor reports actual throttle position.

What does the accelerator pedal position (APP) sensor measure?

The driver’s accelerator-pedal position.

What does the electronic throttle actuator do?

It uses a servomotor to move the throttle plate.

What does the throttle position (TP) sensor measure?

The actual throttle-plate position.

What is the PCM’s role in ETC?

It interprets driver demand and operating conditions, commands the actuator and monitors throttle-position feedback.

What mechanical component does ETC eliminate?

The mechanical throttle cable.

Why can ETC eliminate a separate idle air control valve?

It can adjust throttle opening electronically to control idle airflow.

How does ETC help traction control and electronic stability control?

It allows the PCM to reduce engine power by controlling throttle opening.

How does ETC help cruise control?

The controller can operate the throttle without a separate mechanical cruise-control actuator.

What drivability benefits are listed for ETC?

Smoother acceleration, improved drivability and smoother shifting.

What reference voltage is used by the potentiometer TP sensors in the notes?

5 volts.

How do the two TP sensor signals change as the throttle opens?

One rises from about 0.5 to 4.5 V; the other falls from about 4.5 to 0.5 V.

Why use two opposing throttle-position signals?

They allow the controller to check whether the position signals agree with the expected relationship.

Does an electronic accelerator pedal directly pull the throttle plate open?

No. It reports driver demand to the controller, which commands the throttle actuator.