Electronic Throttle Control System Description - Overview
The electronic throttle control system (ETCS) opens and closes the throttle valve by electronic control. This system consists of a throttle actuator built into the throttle body, the throttle valve and throttle position sensor A/B, accelerator pedal position sensor A/B, the ETCS driver built into the engine control module (ECM)/powertrain control module (PCM), and the ETCS control relay (in the under-dash fuse/relay box) that supplies power to the ETCS driver.
ETCS is a system that opens and closes the throttle valve electronically, it has various functions such as:
- Idle Control Function
Where the throttle position is controlled to optimize idle speed depending on the engine loads when idling.
- Accelerator Control Function
Where the target throttle position is calculated by the throttle position sensor signals to control the throttle valve when the accelerator pedal is pressed.
- VTEC Control Function
Where the throttle valve is controlled in coordination with the VTEC ON/OFF to switch smoothly.
- Transmission Control Function (A/T, CVT)
Where the throttle valve is controlled in coordination with the transmission to reduce shift time.
- VSA Control Function
Where the throttle position is controlled based on a signal from the VSA modulator-control unit.
- Fail-Safe Function
Where the throttle valve is controlled to avoid danger even in the event of a malfunction.