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Guest lmdew

93 Legacy Auto to Standard Trans Swap Elect Help!

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Guest lmdew

The mechanical swap of the standard trans for the worn out auto went well until I turned the key and nothing happened. A second or two went by and I thought of the electrical interlocks for Park and now the clutch disengage switch.

 

I do have the swithches on the clutch, but could not find the connectors in the wire harness, Anyone know where they are?

 

Second, what do I need to do with the large auto connectors in the engine compartment? Is there a jumper harness that installs between the two plugs or are they just not used?

 

Last, on removal of the old brake box I had to remove a gold electrical box, three conectors. This was not in the standard transmission car. I this the transmission control and can it be removed? It will not bolt back up with the new clutch/brake box installed.

 

Thanks for the info

Lmdew@hotmail.com

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Guest Legacy777

The gold box is the TCU, it's not needed with the MT.

 

The connectors that plugged into the AT, I wouldn't worry about them, just leave them alone, or if you want put some electrical tape over them to keep dirt out.

 

There's two things you need to hook up to the new tranny. backup switch and clutch switch. On the AT cars it's called the park inhibitor or something like that. I'm not exactly sure where it is, but if you don't have a manual for the car, I suggest getting one so you can find out which connector or set of wires has the park inhibitor to it. You should be able to then run those lines to the clutch start interupt switch.

 

If you haven't done so, you'll need to snip the MT/AT identifier wire.

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Guest impreza4hire

I did the same thing on a 86 GL-10. The dealer said it wasn't possible, but I proved them wrong.

 

Anyway, here is what you need. The neutral safety switch is causing your problem. Contact must be made to make the engine turn over. Also, unless you changed the ecu, your computer will still adjust the engine for an automatic transmission. So what I did is took an extra breaklight and mounted that onto the clutch and wired that to the "park" position of the neutral safety switch. This allows the car to NOT be started unless the clutch is disengaged (will pass inspection). Then I also wired the safety switch to drive in hopes the ECU would know the car is in the former "drive" postion. With those slight modifications, NO problems and added another 40K miles to the car before I sold it to get an Impreza.

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Guest Legacy777

there is a pin out on the ECU that tells the ECU whether it's a MT or AT. All you need to do is snip that wire.

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Guest lmdew

Thanks for the Info.

 

I jumped the AT wires so the ECU thinks the trans is always in park. It started right up and runs great until it heats up to normal temps. Then it will not idle and runs real rough. (This is the engine that came with the 5sp Trans) so I'm trying to isolate the problem. I believe it is with the air induction system.

 

I've got the reverse lights hooked up and they work fine. I just went from the 5sp plug to the wires on the AT plug. I have not found where the other two wires go coming from the plug.

 

I did not see the trans identifier wire on the ECU pin out Help here would be appreciated.

 

Thanks

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Guest Legacy777

The AT/MT identifier pin is on ECU connector B48 (second largest connector) terminal 20.

 

See if you can confirm that info with your diagram.

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Guest UltimateRX

I would try to get an ECU out of a 93 Legacy with a standard tranny, then you'll only have to wire in the clutch switch. The auto tranny ECU has so many wires related only to the auto tranny that it will take you a long time to isolate all of them. I believe that the auto and manual use that same pins for the starter isolator relay, and there is only one pin that goes to the clutch switch from the ECU, the other goes to ground. I'll look in my 92 Legacy FSM when I get home.

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Guest UltimateRX

Sorry that I didn't get back last night, but I did look in my FSM and it looks like (since I could find the exact schematic that I was looking for that the manual and auto use that same pins on the ECU for the isolator switch, so you would just need to connect the clutch switch (if you went to a manual ECU).

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Guest lmdew

I did the ECU swap yesterday and the D-Check. The ECU is looking for the Neutral SW and the Clutch SW. I hope to have them hooked up today. THANKS FOR THE HELP :>)

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Guest UltimateRX

Boy, I wish that were the same with all ECUs, I have 4 ECUs here, one from a N/A Impreza (96), one from a Turbo Legacy US Model (93), one from a JDM Legacy RS (91), and one from a JDM WRX Impreza (96), none of them have the same connector configuration. A lot of the wires are going to the same places with the same color codes, but you need the schematics and pin out for each if you are trying to convert one to the other.

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