Power Mode Selection - Page 9

WestCoastSVX · #**121** 04-16-2008, 11:42 PM

Winner!

Feel like writing up a little more clear How-To on this method?

The manual button on the gearshift seems the best place for the power mode button as it is easy to switch on the fly (like as soon as you reach freeway speeds).

But retaining the manual mode for diagnostics and the rare occasion one would get stuck in snow or whatever it was made for (I've never used it) would be nice, especially via a switch under the dash.

processengr · #**122** 04-17-2008, 04:25 PM

Hi all!
I took my camera, and went under the dash of the 97, to install the mod and take pix to help in a how-to.After pulling the connector, I found that the A4 position is open like on the 92, but the A6 position is vacant

, instead of the brown-black wire I had intended to de-pin...anyone have the info on where the manual switch has been relocated to?

processengr · #**123** 04-17-2008, 06:22 PM

I grounded A4 on the 97.... No effect. I have to wonder...Since jdm had the power switch all years, I was hoping mine did too... Is this related to the TCU? Did jdm get OBDll? Was TCU changed to accept OBDll? Inquiring minds want to know...

Nomake Wan · #**124** 04-17-2008, 11:10 PM

Quote:

Originally Posted by processengr

I grounded A4 on the 97.... No effect. I have to wonder...Since jdm had the power switch all years, I was hoping mine did too... Is this related to the TCU? Did jdm get OBDll? Was TCU changed to accept OBDll? Inquiring minds want to know...

"No effect?" You do know that the Power light doesn't light up on the OBDII cars, right? Or did you actually go for a drive with the mod in place and didn't feel a difference?

processengr · #**125** 04-18-2008, 05:39 AM

Hi,
I went for a drive to check, I knew from this thread there would be no power light.

Nomake Wan · #**126** 04-18-2008, 05:53 AM

Hmm... that's very odd. To my knowledge, there was no change to the TCU; only the ECU changed from the OBDII switch. And in Japan, their cars still had the Power switch...

Phil will have to weigh in on this one..

svxistentialist · #**127** 04-18-2008, 06:55 AM

Quote:

Originally Posted by processengr

Hi all!
I took my camera, and went under the dash of the 97, to install the mod and take pix to help in a how-to.After pulling the connector, I found that the A4 position is open like on the 92, but the A6 position is vacant

, instead of the brown-black wire I had intended to de-pin...anyone have the info on where the manual switch has been relocated to?

I have a '96 USA wiring diagram, it does not have the Power lamp in the clocks, and the wiring and pin use is different from the earlier models. It could be that the TCU for this model is actually different, it certainly looks that way.

However on the '96 diagram that I have, the Manual switch is definitely connected to pin A6 by a brown and black wire.

So unless your '97 is different again from the '96?........

I really don't know what the situation is Gordon.

Joe

svxistentialist · #**128** 04-18-2008, 07:14 AM

Quote:

Originally Posted by processengr

Hi all!
I took my camera, and went under the dash of the 97, to install the mod and take pix to help in a how-to.After pulling the connector, I found that the A4 position is open like on the 92, but the A6 position is vacant

, instead of the brown-black wire I had intended to de-pin...anyone have the info on where the manual switch has been relocated to?

Gordon, would you mind rechecking something on what pin you grounded?

If your TCU works the same as the earlier ones, the correct pin to ground will be A4 on block B66.

There are three blocks into the TCU, and all three are black.

Based on the '96 wiring diagram, the following is the situation with the three blocks;

B66 has 20 pins/slots. Unused slots are A4, A15, A16, A17 and A18.

B67 has 12 pins/slots. All 12 from B1 to B12 are in use, no slots empty.

B68 has 16 pins/slots. Unused slots are C4, C6 and C9.

Is there any possibility you mixed up the 16 pin B68 with the correct 20 pin B66? As you can see above B68 has slots 4 and 6 idle.

Please get back when you check this out. It's an easy enough mistake to make.

Joe

b3lha · #**129** 04-18-2008, 07:51 AM

AFAIK, ODB2 SVXes were only ever produced for the USDM. It didn't become mandatory elsewhere until after the SVX production finished.

From what I've read on the net, the Subaru implementation of the OBD2 standard does include transmission information, so the OBD2 TCU must have been changed to support that.

There is very little information available about the SVX OBD2 ECU and TCU. If you have the time and inclination to do some research into it then I'd be happy to help you.

Wikedjuggalo · #**130** 04-18-2008, 08:41 AM

O.k Well I had this mode for a few days now and yesterday while driving it showed a check engine light, but the weird thing is it went off after about 30 secs to a min. I check when I got home and got code 38 (I kept counting 39 and 38 but It was 38 sucker goes a little fast) But the hasnt come back on and I was wondering could it have been something to do with this mode, and should I be worried? should I take it out? I read the code and it says something about TCU and ECU short. Like I stated the check engine light has not come back on but I check for codes and it threw that one.

processengr · #**131** 04-18-2008, 10:47 AM

Wow! thanks Joe,
I did have the 16 pin connector...Going back under there now...will report back

b3lha · #**132** 04-18-2008, 11:08 AM

Quote:

Originally Posted by Wikedjuggalo

O.k Well I had this mode for a few days now and yesterday while driving it showed a check engine light, but the weird thing is it went off after about 30 secs to a min. I check when I got home and got code 38 (I kept counting 39 and 38 but It was 38 sucker goes a little fast) But the hasnt come back on and I was wondering could it have been something to do with this mode, and should I be worried? should I take it out? I read the code and it says something about TCU and ECU short. Like I stated the check engine light has not come back on but I check for codes and it threw that one.

The TCU uses the torque signal to notify the ECU that it is changing gear. As far as I can make out, the ECU will report an error if it gets a gear change notification at very low speed and rpm, when you wouldn't expect the TCU to be changing gear.

I don't know why you got this error, unless you really do have a short to ground between the ECU and TCU. If it has gone away now, I wouldn't worry about it.

svxistentialist · #**133** 04-18-2008, 11:12 AM

Quote:

Originally Posted by Wikedjuggalo

O.k Well I had this mode for a few days now and yesterday while driving it showed a check engine light, but the weird thing is it went off after about 30 secs to a min. I check when I got home and got code 38 (I kept counting 39 and 38 but It was 38 sucker goes a little fast) But the hasnt come back on and I was wondering could it have been something to do with this mode, and should I be worried? should I take it out? I read the code and it says something about TCU and ECU short. Like I stated the check engine light has not come back on but I check for codes and it threw that one.

It is really unlikely that this code 38 for the engine torque control signal has anything to do with the Power mod, certainly not if you did the wiring properly ensuring your earth wire hits nothing else except pin A4 in block B66.

In addition the engine torque control signal wire is a Black/Yellow wire running between the ECU and the TCU.

At the TCU side this wire is connected to pin 16 of the connector B68, and this is a 16 pin block connector.

The one your grounded A4 is supposed to be connected to is the 20 pin B66, a different connector, and there certainly should be no physical connection between these two plugs under normal circumstances.

The Black/Yellow wire is connected to your ECU at Pin 20 of the yellow B59 connector. B59 is a 22 pin connector and pin 20 is third in from the RHS of the bottom row. [22 is first, 21 is second, 20 is third]

The voltage at either of these pins is meant to be 4.5V to 5.0V with the ignition on.

You should check that the black connector B68 is firmly pushed into its position at the TCU first, in case you dislodged it a bit while working on the TCU.

Joe

processengr · #**134** 04-18-2008, 11:56 AM

Hi all,
The TCU is rotated 90 degrees different than the TCU mounting in my 92s. The connectors face the floor. The connector that needs to be modded is now the furthest from you (as you look with your head on the floor) instead of the closest to you as on the 92, where the connectors exit from the side of the TCU, and you pull the bottom connector. I thought it was weird that the brake bracket wasn't in the way of the wires as in the 92, but it was getting dark, and I wanted to finish the mod...
Now, I'm off for the test drive...I took lots of pix, and can write what I did, they could be used in a how to...I also found the contact pin/socket is essentially the same as the sockets used in computor motherboard header connectors. Anyone attempting to depin th SVX connector for the first time could practice on one of these first.

b3lha · #**135** 04-18-2008, 12:12 PM

I'm glad you sorted it out. You had me worried.

Quote:

Originally Posted by processengr

The TCU is rotated 90 degrees different than the TCU mounting in my 92s. The connectors face the floor.

That's very interesting. I've been wondering if the OBD2 cars have the same computers as the OBD1 with different software, or if they are completely different computers. Maybe the different mounting suggests that they are actually different computers.

It must make the job a lot easier having the connectors facing down. I have a lot of trouble unplugging the top connectors.