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AnWaRi996

Subaru 6 wire IACV to 3 wire

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Hey guys, I've just purchased a WRXLINK 6+ for my MY99 WRX, but i've swapped in an EJ207 from a 2003 STi. The issue I'm facing is that the new throttle body has a 3 wire idle control valve, but the wiring I have is for the 6 wire stepper valve. I'm just wondering if i can just use the positive, negative, and one of the signal wires (I'm assuming there's 4, so I'd not use the other 3 wires) and just get the Link ECU tuned as a 3 wire IACV?

The old throttle body doesn't fit so reusing the 6 wire valve is out of the question, and I'd much rather use the 3 wire if possible anyway.

Thanks in advance!

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Be easier just to use your current intake manifold and parts.

 

And the stepper motor is not a positive and negative. But yes you will need to source a positive and negative, and configure a PWM output wire from the ecu to the 3 wire if you must change to it.

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The late Subaru 3 wire valves are not like the old school type that have one pin for open and one for close.  The 3 wires are just 12v, gnd & signal.  There will be 12v available there already from the old valve and you can use any one of the existing aux wires, just a ground will be needed.

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I'm in a similar boat, but with a different question:

I am working on a MY00 euro impreza and I'm rewiring the plugs going to the ecu (with V4 plugs) to be able to run the same ECU I run on my 98 type R (wrx4+).,

After some time reading I came to the conclusion that the wrx4+ has only Aux 6 and 8 and is missing aux 5 and 7 that are useful to drive the ICV stepper of the V6. according to the documentation only these 4 are able to do this (why?) and no other.

Is that possible to keep the ver 5-6 throttle body and change the ICV to a 3pin solenoid one? which one would work?

Or how should I proceed with the wr4+ and xs loom Aux to make it work??

thanks

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14 hours ago, dx4picco said:

After some time reading I came to the conclusion that the wrx4+ has only Aux 6 and 8 and is missing aux 5 and 7 that are useful to drive the ICV stepper of the V6. according to the documentation only these 4 are able to do this (why?) and no other.

Correct, only aux 5/6/7/8 can drive a stepper motor.  This is a hardware limitation.  

Im not a subaru guy so cant answer the question on if there are other solenoid type idle valves that will fit easily, but from an electrical perspective that would be the best way forward.    

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6 hours ago, Stevieturbo said:

Why not just keep it simple and use/retain the MY97/98 ISCV the ecu was intended for anyway ?

As I wrote, the car is a V6 (MY00) getting wired for a wrx4+ ecu. So the car has the 6 wire IACV and Neither intake manifold of a v4 My98  nor IACV alone fits on it.

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Adapt and overcome.

 

Or just run without an air bypass and just use timing for idle control.

Or just run an 01+ intake, which gives you better top feed injectors, and a simple ISCV.

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Hey,

So i'm building the adapter harness between V5 harness and v4 ecu.

Is it possible to get detailed ecu pinout from the link ecu v4 and v6?

I mean there are already some clues in the plugin installation manual, but its lacking some pins like the different grounds, cam and crank signals...

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On 1/19/2020 at 9:39 AM, dx4picco said:

Is that possible to keep the ver 5-6 throttle body and change the ICV to a 3pin solenoid one? which one would work?

There's no way to use the 3 pins sensor with the V5-6 throttle body.
The best way to do it would be swapping the entire intake with throttle body, fuel rails, fuel injectors and everything else.

I just did it and it's not a simple job. I also changed the coils to the coil on wire instead of the coil pack.
Will require some rewiring.

Basically what I did:

On the ECU B134 connector, swap:
B134-14 to B134-4
B134-15 to B134-13


Config
Ign 3 and 4 => Ignition 3 and 4
Aux 7 =>  Fan Relay 1
Aux 8 => Fan Relay 2
Aux 5 => ISC

Wiring:
Ign 1, 2, 3 and 4 wired to the coils
ISC Signal to Aux 5 wire
throttle body map to the oem map wires

Beside that you will need a longer intercooler hose and some trim on the bottom part of the water reservoir to be able to attach on the same place.

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Thanks alot for this batch of information.

I will reciev in the next days the forester turbo ecu that will be the donnor of the female plug for the adapter harness.

I'll start this project by running without idle valve and stock manifold and go from there.

There will be for sure a time where i'll swap for a new age sti manifold, but not that close of a timeline.

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