Electronic Throttle Control System (ETCS)

The ETCS consists of throttle body, accelerator pedal position sensor, Throttle Position (TP) sensor, throttle control motor, magnetic clutch and Engine Control Module (ECM). ETCS uses the ECM to calculate throttle valve opening in the throttle body in relation to driving conditions. ETCS controls idle speed control system and cruise control system operation. Accelerator pedal position sensor is mounted on the throttle body and is integrated with throttle lever which attaches to the throttle cable. Accelerator pedal position sensor converts amount of accelerator pedal effort into 2 different types of output signals and delivers input signals to the ECM. The TP sensor delivers input signals to ECM to indicated throttle valve opening.

The ECM uses these input signals to operate the throttle control motor to obtain proper operating speeds in relation to accelerator pedal effort and engine speed to obtain proper idle speed and provide cruise control operation. Throttle control motor operation is also synchronized to the traction control system. The throttle control motor is mounted on side of throttle body and operates the throttle valve on the throttle body by the use of a magnetic clutch.

In the event of a ETCS malfunction, Malfunction Indicator Light (MIL) on instrument panel will be illuminated and Diagnostic Trouble Code (DTC) will be stored in the ECM. If malfunction exists, magnetic clutch will be disengaged, allowing spring pressure to close the throttle valve. When magnetic clutch is disengaged, throttle control motor will not operate the throttle valve. If ETCS is shut off, accelerator pedal may be used to operate throttle valve for vehicle operation in limp mode by using limp mode lever on the throttle body to operate the throttle valve.