2008 thru ?, ej257b, b21 plug

[matteo92065]

I'm working on some Dual AVCS motors for an 818. I don't know what year each motor is, and I don't have the factory manual for each year. I only have the 2011 manual.
It's my understanding that nothing changes from 2008 to 2013ish in terms of motor functions. These motors use a single plug for the motor harness, Subaru calls it B21.

My question is; are all the STI engine harnesses the same from year to year??? Can I keep these motors built with the different wiring harnesses? Or do I have to move one harness from motor to motor??

Attached is the 2011 STI B21 plug with functions overlayed. Thanks
fyi, other years and models also use this plug, 2006 impreza for example. BUT the wires are very different. Why wouldn't they have a standard layout and just add to it?

2011 b21.JPG
IMG_9202.JPG

[matteo92065]

We looked at a few harnesses and they are all different, even though they all have the same motor options.

[Junty]

Good question - however I agree with 'Build 222' - all different - year to year and model to model. I have 2011/2012 2.5 in my 818 from WRX (not Sti) however every wire is different to your image. I believe US versus JDM could also be different? I suggest care and trace each wire!