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Idle control valve issue

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Posted (edited)


I am really messed with this IAC valve thing. My car has rotery solenoid valve as IAC. RSC coil for closing side and RSO for opening side. ECU provides a PWM to one and inverted to the other. (i.e. If RSO gets PWM with 75% duty cycle, RSC gets its inverted PWM which is 25%. This makes a resultant force to IAC open 50%.)

My data sheet gives the RSC and RSO values attached herewith. Please see picture 1.You can see resultant of IAC is at idling with no AC, is "closed".

But when I check it in my car, the resultant of IAC at idling with no AC is,  "opened". Please see picture 2 & 3.

Picture 2 is RSO. Picture 3 is RSC. ( eventhough it should give inverted to each other please disregard it since it's an issue with oscilloscope.i.e. time shift does not shown by oscilloscope.) 

1) I checked for vacuume leaks and none found.

2) I also checked these RSC, RSO values at different throttle adjusting screw setting. No change. 

3) Checked IAC with values in datasheet and it was OKAY.

4) Also I checked idling speed which is at around 750 rpm.

5) Also I checked rpm when AC switched on which is increased from 750 to around 900.

Pic 1 - Image 0233 - first picutere is without AC.

Pic 2 - Image 0448 - RSC without AC

Pic 3 - Image 0450 - RSO without AC


What is the issue in my car? Why can't I get the setup in the datasheet? 







Edited by Ted

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