ST20V VVTi wiring Question - 2 wires?

[Futo_gt86]

Hi

Long time listener, first time caller.
Serioulsy, did search and can't see where this is covered.

Wiring up me sedan, and stumbled on this...
Bit of a grey area.

ST20V VVTi actuator has 2 wires,

Red and Black
Which one does what?
Its it as simple as it looks, a +ve and a -ve?

How does stock ECU work the actuator,

Is it -ve switched through the ECU for 1 position at certain rev, and returns by itself?
Or does it switch reverse polarity to off position as well?

If I follow what was already in place looking at what was there my simple brain tells me:
Red = Aux Output on ECU
Black = 12V power switched by 12V IGN

I was going to wire Black to +ve 87 pin on relay, and red to -ve aux out put on Microtech.
But before I go ahead, I would like some to pull me up if I'm wrong.


Any help would be much appreciated.

Thank you!
Ali

[Matt]

Don't think u need a relay as the ecu only provides the earth. On about 2k and off around 5k

[Futo_gt86]

Relay is for switched power supply only, not to trigger.
This was wired to constant source, which I in my mind ain't right.

Sorry, should be more clear;-

Current wiring from previous owner is
Black +ve
Red -ve

I would like to confirm that
A> this is right, (common sense tells me normally its the other way around)

And ask

B> Been a while since I got into AUX output screen on Microtech, and I will have to double check, but from memory this LTX8 version I am using only has 1 (-ve) trigger point for on/off to set output.
What potential issues can I cause from running VVTi advance all the way up to limiter?

Ali

[Matt]

If u don't have an answer i'll check it tomorrow for you on mine as to which pin on the plug has power.

But look here



Plug k is the one, and pin 1 with power. I know for certain the iscv power wire is black.

If u run it up to the limiter u won't make as much power as the timing will be too far advanced... it gives u ~30 degrees of timing.

Put it on ignition power as it was from factory and let the ecu earth it directly.

[Futo_gt86]

Thank you sooooo much for the info.

I'm pretty sure you can set this thing for different switching on / off points points, however this is an older MTX8 model, its like almost 10 years old.
My Bro has a Mircotech dash unit that will work with it, I'll lend it for the day and open up AUX output screen and play around with it.
I'm sure I'll figure something out.

Cheers,
Ali