Suzuki 2006 SX4, Service Manual

Page: 55 / 1478

Engine General Information and Diagnosis: 1A-11
Description of Electric Throttle Body System
S6RW0C1101017
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 (TP) sensors
• APP sensor assembly: Accelerator pedal, 2 APP 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 engine 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 TP sensor (3) included in the throttle
body (2) and compares it with the above calculated optimum throttle valve opening. When there is a difference
between them, ECM controls the duty ratio (100% – 0%) of throttle actuator control according to this difference to drive
the throttle actuator (motor) (4) included in the throttle body. When there is no difference, ECM controls the duty ratio
of throttle actuator control 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, TP 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
throttle actuator control relay (8) to stop controlling the throttle actuator. When the throttle actuator control relay is
turned off, the throttle valve is fixed at the opening of about 7
°
from its completely closed position (default opening) 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
1
2
17
3
5
6
7
8
9
10
11
12
13
14
15
16
18
I4RS0B110007-02
6. CPU 11. APP sensor (main) signal 15. Drive signal of throttle actuator
7. Drive circuit of throttle actuator 12. APP sensor (sub) signal 16. Power supply of throttle actuator
9. From “THR MOT” fuse 13. TP sensor (main) signal 18. Control signal of throttle actuator control relay
10. From main relay 14. TP sensor (sub) signal