Quick question about ICV..

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Brdjo
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Post Mon Mar 21, 2016 7:52 am

Hi to all once again :)

If I assume right, the ICV is powered by ECU directly, and the voltage should be 7-7.5V on both terminals..? (motronic 1.3)

On my car the voltege on one terminal is 9v and second 4v, always.. Tried different ECU, same thing.. I was wondering why is that so and could this indicate a some kind of problem?
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Brianmoooore
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Post Mon Mar 21, 2016 9:48 am

Voltages on pins depend entirely on what the ECU is trying to make the ICV do, and you haven't said what engine. M20 and M40/42 ICVs are totaly different from each other, and work in completely different ways.
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Brdjo
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Post Mon Mar 21, 2016 10:03 am

M20 engine, 172 ECU.. I did measurements few times, cold engine, hot engine and values are the same every time..
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Brianmoooore
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Post Mon Mar 21, 2016 10:15 am

In that case, the ICV will have three wires going to it, not two. It's effectively two electric motors working against each other - one trying to close the valve, and the other trying to open it.
You haven't said what the problem is that's leading you to investigate the ICV.
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Brdjo
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Post Mon Mar 21, 2016 10:23 am

Yes three wires are there, middle one is ground.. No problem, idle is fine, just wondering is that normal, because i read somewhere that the voltage should be equal on both terminal side when ignition is on..
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jslot
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Post Mon Mar 21, 2016 12:41 pm

I think when the ignition is on but the engine is off, the ECU has the ICV wide open, which would mean the voltages would not be the same.
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Brdjo
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Post Mon Mar 21, 2016 1:31 pm

Hmm makes sense, but I wonder why the values stays the same after turning engine on.. And every other time I check, on ignition or engine runing.. :)
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Brianmoooore
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Post Mon Mar 21, 2016 1:37 pm

The voltages will be whatever the ECU determines is required to keep the idle at the correct speed. Any published figures you have found are meaningless.
The voltages will be affected by the exact setting of the throttle butterfly stop, any air leaks into the inlet tract, and the load on the engine.
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Brdjo
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Post Thu Mar 24, 2016 6:28 am

Thanks for info, just I was looking for.. :)
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