Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Idle air control System/ Circuit / Circuit description
Toyota Corolla (E120): Circuit description
The rotary solenoid type idle air control (iac) valve is located under the throttle body and intake air bypassing the throttle valve flows into the iac valve through the passage.
In this way the intake air volume bypassing the throttle valve is regulated, controls the engine speed.
The ecm operates the iac valve only to perform idle–up and provide feedback for the target idling speed.
Monitor description
The idle speeds are determined depending on the volume of air that passes through the iac valve. When the volume is large, the idle speed becomes higher. When the volume is small, the idle speed becomes lower.
The iac valve controls the air volume that bypasses the throttle valve. The engine control module (ecm) sends duty signals to the iac valve and drives the iac valve stepper motor to determine the air volume that bypasses the throttle valve.
Although the ecm regulates the idle engine rpm with the feedback control in several vehicle stopped, actual idle rpm does not reach the targeted rpm and a learned valve angle of the idle air control (iac) remains at the maximum or remains at the minimum, the ecm determines to detect malfunction in the iac system.
Example: if the rpm difference between the targeted and actual idle engine rpms exceeds 200 rpm (*1) with the vehicle stopped in an idle, and this occurs 5 times, or if the learned value angle of the iac remains at its maximum or minimum angle for 5 seconds, p505 is detected.
P0511 is detected as an open/short circuit in the iac if the rate of duty signal input to the iac valve has stuck at 0 or 100 %.
*1: Threshold rpm is varied by an engine load.
Monitor strategy
Typical enabling condition
Typical malfunction thresholds
Component operating range
Wiring diagram
Other materials:
Console box
Slide the lid to the rear most
position. (vehicles with a
slide function)
Lift the lid while pulling up the
knob.
■Slide function (if equipped)
The console box lid can be slid forward or backward.
WARNING
■Caution while driving
Keep the console box closed.
Injuries may result in the ev ...
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To enter 10-speed sport
sequential shiftmatic mode, shift
the shift lever to M position.
Gear steps can then be selected
by operating the shift lever or
paddle shift switches, allowing
you to drive in the gear step of
your choosing.
Upshifting
Downshifting
The gear changes once every time
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Dialing from call history
You can make a call using the call history, which has the 3 functions below.
: calls which you missed
: calls which you received
: calls which you made
1 Display the phone screen.
2 Select “Call History” tab.
3 Select or the desired entry from
the list.
► When
is selected
4 C ...