Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-9
Air Intake System DescriptionS7RS0B1101006
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 “Description of Electric Throttle Body System”.), 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 combusti on 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 “Description of Electric Throttle Body System”).
Description of Electric Throttle Body SystemS7RS0B1101007
The Electric Throttle Body System consists of electric throttle body asse mbly, 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 pe dal, 2 accelerator position sensors
Operation Description
ECM (5) detects opening (depressed extent of pedal) of the accelerator pedal based on signal voltage of the APP
sensor (1) and using that data and engi ne operation condition, it calculates the optimum throttle valve opening. On the
other hand, it detects the throttle valve opening based on the signal voltage of the throttle position sensor (3) included
in the throttle body (2) and compares it with above calculated optimum throttle valve opening. When there is a
difference between them, ECM controls the duty ratio (100% – 0%) according to this difference to drive the throttle
actuator (motor) (4) included in the throttle body. When th ere is no difference, ECM controls the duty ratio to about
15% to maintain the throttle valve opening . In this way, the throttle valve (17) is opened and closed to achieve the
optimum throttle valve opening.
In this system, as the thrott le position sensor and APP sensor have 2 sensors (main and sub) each, highly accurate
and highly reliable control and abnormality detection are assured. Also, when ECM detects an abnormality in the
system, it turns off the th rottle actuator control relay (8) to step controlling the throttle actuator.
When the throttle actuator control relay is turned off, the throttle valve is fixed at the specified opening below from its
completely closed position (default openin g) by the force of the return spring and open spring included in the throttle
body.
This throttle body is not equipped with IAC valve for idle speed control. Idle speed control is done by the throttle
actuator which opens/closes the throttle valve.
4 2
1
3
5
6
I5RW0A110006-02
Downloaded from www.Manualslib.com manuals search engine Engine Electrical Devices: 1C-3
Throttle Valve Operation Check1) Remove air cleaner outlet hose.
2) Turn OFF ignition switch.
3) Move throttle valve with finger to its full open position and check that it moves smoothly.
4) Move throttle valve with fi nger to its completely
closed position and check that it moves smoothly.
5) Take off finger from throttle valve (1) which is at full open position and check that it moves smoothly by
its return spring and open spring force back to
default position (2) (positio n where throttle valve is
open by 6 ° from completely closed position).
6) Take off finger from throttle valve (1) which is at completely closed position and check that it moves
smoothly by its return spring and open spring force
back to default position.
If check result is not satisfactory, replace electric
throttle body assembly. Electric Throttle Body
Assembly Operation Check
1) Remove air cleaner outlet hose.
2) Turn ON ignition switch.
3) Depress accelerator pedal gradually and check that throttle valve moves smoo thly until it opens fully.
4) Release accelerator pedal depressed in Step 3) and check that throttle valve (1) moves back to default
position (2) (position where throttle valve is open by
6° from its completely closed position).
If check result is satisfactory, electric throttle body
system is in good condition. If check result is not
satisfactory, proceed to next step.
5) Perform “Accelerator Pe dal Position (APP) Sensor
Assembly On-Vehicle Inspection (Electric throttle
body model)”, “Throttle Actuator (Motor) Check” and
if check results are not satisfactory, replace electric
throttle body assembly.
If check results are satisfactory, wire circuit and/or
ECM are faulty.
Throttle Actuator (Motor) Check 1) Turn OFF ignition switch.
2) Disconnect connector from electric throttle body assembly.
3) Measure resistance between “M1” terminal (1) and “M2” terminal (2) of electric throttle body assembly.
If measured resistance is out of specified value,
replace electric throttle body assembly.
Throttle actuator (motor) resistance
0.3 – 100 Ω at 20 °C, 68 °F
I4RS0B130004-01
1
2
I4RS0B130005-01
1
2
I4RS0B130005-01
2 1
I4RS0B130023-01
