Air Intake System Description
The main components of the air intake system are air cleaner (1), air cleaner outlet hose (2), electric throttle body (3)
(for the details, refer to "Electric Throttle Body System Description".), and intake manifold (4).
The air (by the amount corresponding to throttle valve (5) opening and engine speed) is filtered by the air cleaner,
distributed by the intake, and finally drawn into each combustion chamber. Electric throttle body is not equipped with
IAC valve for idle speed control. Idle speed control is done by the throttle actuator (6) which opens/closes the throttle
valve. (For the details, refer to "Electric Throttle Body System Description".)
Description of Electric Throttle Body System Calibration
ECM calculates controlled opening of the throttle valve on the basis of the completely closed throttle valve position of
the electric throttle body system. The completely closed position data is saved in memory of ECM. However, the
completely closed position of the throttle valve of the electric throttle body system (signal voltage from throttle position
sensor when throttle is completely closed) differs one from the other depending on individual differences of the throttle
valve and throttle position sensor. As such individual differences must be taken into account for controlling the throttle
valve, it is necessary to register the completely closed throttle valve position data in ECM. When such data is
registered in ECM, it is saved in RAM (memory) of ECM and used as the base data for controlling the throttle valve.
This data is cleared, when any of the works described in "Precautions of Electric Throttle Body System Calibration" is
Also, after replacement of the throttle body and/or APP sensor assembly, the completely closed position data in
memory of ECM must be cleared once and a new one must be registered, or ECM cannot judge the complete closure
For the procedure to register such data, refer to "Electric Throttle Body System Calibration in Section 1C". (After the
completely closed position data is cleared, ECM, for the first time only, opens and closes the throttle valve for about 5
seconds after the ignition switch is turned ON position, for registration of the completely closed throttle valve position.
If the engine is started during this registration process, such symptom as "longer cranking time" or "slow rise of
revolution speed immediately after start-up" may occur. However, turning OFF the ignition switch once and restarting
will set correct registration.)
Electric Throttle Body System Description
The Electric Throttle Body System consists of electric throttle body assembly, accelerator pedal position (APP) sensor
assembly, ECM and throttle actuator control relay.
Among them, assembly components are as follows.
• Electric throttle body assembly: throttle valve, throttle actuator, 2 throttle position sensors
• APP sensor assembly: Accelerator pedal, 2 accelerator position sensors
Engine General Information and Diagnosis: