Single AVCS vs Dual AVCS in your Subaru

Single AVCS vs Dual AVCS in your Subaru

Jul 28, '21
AVCS Solenoid Subaru AVCS Explained



In Subaru cars there are 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.

Take a look here for EJ20XY Specifics.


Single AVCS

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



Also known as Quad AVCS, Dual AVCS means there is AVCS on the two intake cams as well as the two exhaust cams. All models of Dual AVCS engines are also run by CANBUS equipped ECUs. So for now, it would require a wiring harness merge to run the engine on a standalone ECU. We hope to make it work with the OEM ECU in the future but we aren't quite there yet.


How do I make the AVCS work in my swapped car?

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


For some cases it's simple - For an 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.


For some cases it's more complicated. If you're doing an 2005-2006 Legacy GT/Outback XT with an EJ20XY you can use the JDM ECU and swap the immobilizer chip so it runs. From there we would send a custom AVCS kit to make the dual AVCS work. This assumes a EJ20XY with two wire cam position sensors.


For other cases it's more difficult and it would be best to contact us before a project is started.


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.