AT/MT identifier pin

I was doing some homework on this auto to manual swap before I attempt it, and one of the idea's that I had was to find out if the AT/MT identifier pin in our ecu's was like that of the older Legacys. I used member wsmith30134's car as my MT Guinea pig.

The pin is located on connector B134 pin 34. On the MT I measured 0v in reference to ground.

On my AT the pin was there on the ecu but there was nothing in the connector at that pin. I lucked out and actually had female crimp connector that fit the harness so I was able to get a reading to ground.

I measured 12v! The next step is to get my hands on Wes's car again and cut the wire going to that pin and measure what voltage he's getting from the ecu to ground. I'm hoping it is a 12v signal. If I'm that lucky I will then pull the rom with romraider and see if identifies his MT as an AT.

If that's the case then I will try grounding out the 12v signal on my ecu and disconnecting the TCU completely.

I was able to borrow wsmith30134's car again, and cut the wire to B134 pin 34. Sure enough I measured 12v from the ecu to ground, just like on the ecu on my car.

This means that the only requirement to make the 5eat ecu behave like the 5mt ecu is to ground out pin 34 on connector B134. Which is not any different than on the older Legacys.

In the next couple of days I will try disconnecting my TCU and ground out this pin and see if I get a TCU communication error. If it works out like I think I will I'll start swapping parts this weekend.

I was doing some homework on this auto to manual swap before I attempt it, and one of the idea's that I had was to find out if the AT/MT identifier pin in our ecu's was like that of the older Legacys. I used member wsmith30134's car as my MT Guinea pig.

 

The pin is located on connector B134 pin 34. On the MT I measured 0v in reference to ground.

 

On my AT the pin was there on the ecu but there was nothing in the connector at that pin. I lucked out and actually had female crimp connector that fit the harness so I was able to get a reading to ground.

 

I measured 12v! The next step is to get my hands on Wes's car again and cut the wire going to that pin and measure what voltage he's getting from the ecu to ground. I'm hoping it is a 12v signal. If I'm that lucky I will then pull the rom with romraider and see if identifies his MT as an AT.

 

If that's the case then I will try grounding out the 12v signal on my ecu and disconnecting the TCU completely.

 

[ATTACH]84243[/ATTACH]

 

[ATTACH]84244[/ATTACH]

 

[ATTACH]84245[/ATTACH]

If you disconnect your TCU you WILL loose cruise and ABS. TCU controls both of those.

If you disconnect your TCU you WILL loose cruise and ABS. TCU controls both of those.

From what I can tell the getting the cruise control to work is only a matter of switching disconnecting the TCM from pin D9 and adding the neutral position switch inline between pins D9 and D2.

As for the ABS it looks like the only signals from the TCM going to the ABS module are from A3 and A4 to the can-joint connector. I thought the speed sensors at the wheels are what control abs and the speedometer not the sensors in the transmission. I could be wrong though.

Removing the TCU will result in having to do away with the back-up light relay, but that will simply be replaced by the back up switch in the 5mt. I'm not 100% removing the TCU will work, but its worth a shot.

I thought the speed sensors at the wheels are what control abs and the speedometer not the sensors in the transmission. I could be wrong though.

Tranny relies on the front and rear speed sensors for shifting. When one or both fail, it relies on the ABS sensors.

Does that help?

Tranny relies on the front and rear speed sensors for shifting. When one or both fail, it relies on the ABS sensors.

Does that help?

I knew about the speedometer and the ABS using the speed sensors at the hubs, but not anything about when the trans speed sensors fail.

Rick, YOU ARE THE MAN! If time and money werent issues for me I'd be right there with you doing this swap.

Well I still have to make this swap work first before I celebrate, but thanks for the encouragement. lol

So does this mean you will be kicked out of your 5eat pride club????

For those of you that don't know Wes, he is a complete smartass. But he will be helping me with this swap.

So does this mean you will be kicked out of your 5eat pride club????

I recently got kicked out of my 4EAT club. It is worth it.

I recently got kicked out of my 4EAT club. It is worth it.

http://legacygt.com/forums/showthread.php/05wrx-5-spd-98-legacy-gt-wgn-auto-5spd-conversion-136840.html

and finaly .. have you been able to get the cruise to work ? and abs to work correctly ?

The ABS sensors are located at the hubs so the ABS works just as it always has. The cruise won't work as long as you have a can-bus communication error. I never use the cruise control so it is not an issue for me.

Which cars does this apply to? Is it just me or was that left out of the entire conversation?

Personally I'm curious about 05 OBXT 5AT to 06 LGT-B 6MT.

I looked into this years ago and even shoved a wire into an ecu pin and grounded it. I assume I did a bad job. Now that I'm trying to do a better job, I'd like to be a little more certain. Getting in there for wiring up my own neutral safety switch. Amazing how I could have 5 good years of driving with my swap without ANY transmission wiring.

I see you both have 05/ 06 LGT's and is perfectly applicable to my car and trans.

Any luck with the TCU delete? Was can bus speedo and cruise control something you could keep working without the TCU?