Single AVCS vs Dual AVCS in your Subaru

Jul 28, '216 comments
Subaru vehicles have two types of AVCS (Active Valve Control System). Want to know what AVCS means? Check out this blog post. Subaru has two models of AVCS engines which we break down below.

Single AVCS

Also known as Intake AVCS, Single AVCS means the engine has AVCS on the two intake cams (left and right intake). 

Dual AVCS

Also known as Quad AVCS, Dual AVCS means there is AVCS on the two intake and exhaust cams. All Dual AVCS engines are also controlled by CANBUS-equipped ECUs.

 

How do I make the AVCS (single or dual) work in my swapped car? 

Unfortunately, this is not an easy answer. Since Subaru has so much variation in its wiring, it all depends on what swap was done.

 

2002-2005 USDM WRX Chassis (Non AVCS to Single AVCS)

This case is a simple one. For a 2001-2005 JDM STI or WRX into a 2002-2005 USDM WRX, all that is needed for the single AVCS to work is the iWire AVCS Bulkhead Kit and/or the iWire AVCS Intake Manifold Kit.

 

EJ20XY Engines with 2005 or 2006 Legacy GT/Outback XT - (Single to Dual AVCS)

If you're doing a 2005-2006 Legacy GT/Outback XT with an EJ20XY, you can use the JDM ECU and swap the immobilizer chip to get it running. We would send a custom AVCS kit to enable dual AVCS. This assumes an EJ20XY with two wire cam position sensors. 

 

EJ20XY Engines in any Single AVCS 3-Wire Cam Position Sensor Platform - (Single to Dual AVCS)

This means a simple ECU swap for a Dual AVCS engine into the vehicle is not possible. For those who are set on getting Dual AVCS working (except for 2005/2006 Legacy GT and Outback XT) in their single AVCS vehicle, the best solution would be to find a plug-and-play standalone ECU for the chassis and then add in the additional wiring for the exhaust side cam sensors and AVCS solenoids. 

The required connectors are linked below.

3-wire Camshaft Position Sensor Connector

AVCS Solenoid Connector

Take a look here for EJ20XY Specifics.

 

What if I run the car without the AVCS hooked up? 

Yes, the engine can run the car without the AVCS hooked up. It doesn't hurt the engine but it also keeps it from running at peak performance since the cam is sitting in the least advanced position.

#AVCS

Comments (6)

iWire on Jan 7, '22

Hi Carl, This blog post will give you your options – https://iwireusa.com/blogs/iwire-university/ej20x-and-ej20y-dual-avcs

carl noel on Jan 7, '22

just did the ej20x swap in my 2013 wrx not to long ago, so from what ive read seems like the only way id get the exhaust AVCS side to work is by either swapping to the jdm harness and ecu and swapping the immobilizer from the usdm to the jdm ecu or or buy the jdm harness for the sensor with a standalone(haltech)?

iWire on Dec 16, '21

Hi Axel, You’ll want to look at this blog post and utilize the new longblock and leave the wiring intact for your 2014 WRX since it is CANbus equipped – https://iwireusa.com/blogs/iwire-university/my-subaru-engine-blew-up-what-should-i-replace-it-with

Axel Rodriguez on Dec 16, '21

2014 wrx ej20y swap, the jdm ej25 blew and I am doing the ej20 swap to get up and running again. Is there anything g specific that has to be done in order for this 2.0 jdm engine to work in my usdm chassis. Any help would be greatly appreciated

Anonymous on Nov 22, '21

Hi John, Please send us an email to info@iwireusa.com so we can chat specifics like which engine you have and what chassis it is installed into. Here’s a little more about Dual AVCS in the meantime – https://iwireusa.com/blogs/iwire-university/ej20x-and-ej20y-dual-avcs

John Milare on Nov 19, '21

I have a dual avcs engine trying to talk to a 2005 WRX ecu. What are my options?

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