1-14 GENERAL INFORMATION
Technical Information-Electrical Throttle Valve (ETV) System
1. Accelerator Position Sensor 1 and 2
The accelerator position sensor senses the rider's intention on throttle operation and transmits it
to the ECU as an electrical signal. Each incorporating a built-in variable resistor, the two sensors
independently work to detect the position of the pulley shaft.
2. Throttle Position Sensor 1 and 2
The two contact-free, Hall-element type sensors independently work to detect the opening angle
of the throttle valves.
3. ETV Actuator (DC Motor)
In response to the signal from the ECU, the ETV actuator (DC motor) moves the throttle valves
quickly to the target position via three gears.
Receiving the accelerator position sensor signals, the ECU operates the ETV actuator to move
the throttle valves to the target opening angle, and verifies that the valves are in the target position
by the throttle position sensor signals. The ECU performs the fail-safe control in case of a system
failure. It also performs the cruise control function in the models equipped with cruise control
The ECU has a large-scale integrated circuit (LSI) to monitor its central processing unit (CPU),
and the CPU also has the function to monitor the LSI – they mutually monitor with each other for
their correct operations.
CPU (Central Processing Unit)
LSI (Large-scale Integrated Circuit for Monitoring CPU)
A. Fuel Injection Control Section
B. Cruise Control Section
C. Fail-safe Control and LSI Monitoring Section