As requested by Phil, am making a new thread which will eventually get compiled into a how-to... I only got as far as the experimentation stage, so hopefully someone will think of a better solution. I know a switch would be the proper way, but it's getting the switch into position A4 permanently and finding a good permanent ground besides the ECU diagnostic cable that will require the most thought. Maybe a simple kit will come out of it.
In any case, to add a POWER Mode switch to a USDM car like the JDM cars have, you have to ground pin A4 on the TCU. This is (fortunately) found on the bottom-most wiring harness on the TCU (when looking up at it with your head on the floor). The row of pins on the side the locking clip is on (the "top") will be filled in with wires except for the fourth spot from the "bottom." Do not confuse this with the other row, which has many missing wires (though both possible "fourth" positions have wires on that side).
Here is a picture of the harness, including where to put the wire. Please note that your harness will have more wires than mine since I used a few to make this mod.
My experiment consisted of merely a length of wire, one end of which was pushed into the TCU wiring harness from the back, and the other end of which was wrapped about the blue diagnostic wire for the ECU.
To make this a little easier to understand, here are the photos of the installation.
First, this is how it looked. Problem is that you couldn't have your foot on the dead pedal or you'd knock the wire out. Thus the need for a more permanent solution.
Next, the best picture I could get of the wire going into the TCU. When the harness isn't in the TCU it's really easy to see where it goes. But with it in there are so many wires that it's confusing. Please disregard the Alpine iPod unit, as it is not standard equipment.
And the other end of the wire, wrapped up with the ECU diagnostic wire. Gotta love having an efficient ground so close to the work area. Thanks, Subaru!
And finally, the result of all that work... sweet, sweet POWER mode. Note the revs and speed; bet'cha can't do that with
your USDM SVX! Yet...
That's all for my part. Maybe one of the wiring guys can have a look at the harness and the pedal area and find a good place to stuff a wire and a switch.
