A single pole switch would work fine with the addition of a relay, but I don't think USDM cars have an Econ switch, so it's a moot point.
I am planning a software mod along these lines for UK SVXes just as soon as I get my hands on a UK ECU.

But they must have an Econ light position, judging by what the guys are saying?

And if they don't have Econ, then what does the switch on the shifter do for them? Is it Manu?

I'm pretty sure I have a spare Phil. I'll check. PM me with your address and I'll loan you one.

Joe

This is correct. The software in the UK means that grounding A4 makes power mode completely unavailable. Whereas in the US, Japan, NZ, etc... grounding A4 enables power mode exclusively.

Meaning that though you could wire up the "ECON" light to come on when A4 is not grounded, it would be meaningless; you could still get power mode to come on through the tried-and-true mash-the-gas method. ;)

Thanks Nomake.

Since you don't use the econ button and econ light, what would be good to achieve would be to use the shifter button [which I am assuming is MANU on your cars, but nobody has confirmed yet] and rewire it so it is dual purpose.

In the ON position, like it is wired now, it could activate the MANU map in the gearbox.

In the OFF position it could be wired to ground pin A4 and to light up the ECON bulb. This would give you Power mode all the time which would be indicated by the Econ light. I reckon this would be useful to the OBD2 guys whose Power light does not come on.

If you feel the need for more sedate driving, then switch on Manu. The SVX has buckets of torque for starting in 2 range. I drove my first SVX for a year with only 3 range working until I found someone who could fix the gearbox;):D


Joe

I would be happy to confirm for you that the US shifter button is indeed "MANUAL." Just like my old Legacy! :D

http://img174.imageshack.us/img174/4...ewpartsur3.jpg

I do have to comment on your concept, though... the "MANUAL" switch is a single-pole switch, so it merely makes or breaks the connection to the manual function of the TCU. Much like the JDM "Power Mode" switch works, and the UK's "Economy" switch.

Therefore, wiring it as dual-purpose would be somewhat tedious. Not saying you can't do it, far from it; but it would be a tedious excercise for little gain.

Also, it is my understanding that, like the ECON light, the POWER light still exists but is merely not lit up by any normal functioning of the car. Therefore, rather than wiring the ECON light to display power mode, why not do the same amount of work required and wire the POWER light instead? ;)

There is a fundamental difference between the Econ light and the Power light.

The Power light is controlled by the TCU. The TCU switches on the power light when power mode is engaged. The Power light is not wired to the Power switch at all.

The Econ light is wired to the Econ switch. The TCU cannot switch it on or off. It will be on when the Econ switch is on and off when the switch is off, regardless of what is happening inside the TCU.

My objective, once I figure out how to mod the TCU, will be that with the Econ switch on (and therefore the Econ light) the TCU will operate in Normal mode (power mode will come on when you mash the pedal). With the Econ switch off, the TCU will operate in Power mode (the power light will be on). The current Econ mode functionality will be removed.

Of course I haven't looked at the UK TCU yet, and I am assuming that the function that selects the shift mode is only slightly different to the JDM one.

I wonder why the power mode was removed from the OBD2 cars. If they have the same TCU hardware as our cars, then they only have 16K of ROM. Perhaps Subaru had to cut some features to make room for the OBD2 functions? I guess we'll figure it out in due course.

i dont understand why on my 96 the power light is connected but it never comes on.... hmmm, im going to put in a switch for my power mode , to much hesitation when its engaged!! :barf:

power mode is still there in obdII cars, there is just not a light for it, dont know why , but ALL the svxs had the power light whether or not it worked ( lit up at mash of pedal) my mechanic at subaru gave me this info when I was having them look at a possible purchase of a 97. the tcu still functions in all svxs , per what i was told , the same. the obdII however has all the different circuitry for the change from obdI to obdII so the POWER light was taken out ( not working).

I think the manual switch would be a good candidate for this modification, seeing as manual is pretty much worthless on (USDM AWD spec cars, anyway)

The only time I ever use it is to pull codes from the TCU, and I feel this could be accomplished by a switch in the bin in the center console.


Patrick

I'm telling you, it's not your TCU/transmission's fault... :rolleyes:

Ooh, even better... Wire the ground side of the ECON light to the positive side of the POWER light.. That way when the power light is off, the econ light is on, and when you mash the throttle, power mode will kick in, and turn the econ light off (since both sides of the light would be @ 12V

I'm pretty sure that's how you do it anyway, I did the same thing with the marker lights on my 87 Subaru hatchback, so they'd blink with the turn signals (Ground of marker to hot side of turn signal)

Phil is planning to mod the software [or firmware] in the box. What I was trying to do was to offer the Manu button as a means of switching between Normal [but without 1 range] and Power [but with the Econ light showing Power was on]

I purposely did not choose to connect live to the Power light for this as the Econ light was not in use in US TCUs, but the Power lamp is used to show codes etc for OBD1s.

That way the mod would be simple and work for all years of the SVX.

:)

William, we don't get OBD11 over here. I'm presuming that with the change, you no longer have the option of plugging in the wire and getting the flashing codes, is that correct?

If so, it would mean the primary purpose of the Power light to show problems on startup and show codes is no longer needed. Maybe that's why it was deleted?

Joe

So. Has anybody tried Nomake's power mode mod on an OBD2 SVX?

Cruisen_15 did, and it worked; but his engine doesn't run right so he didn't really see a benefit from it.