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  #1  
Old 04-25-2011, 07:39 PM
Subie-Addict Subie-Addict is offline
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Location: Maine
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trans flip flop

Ok so I'm taking my stock 4eat out and switching it with the 4.44 from my legacy and I'm gonna run an ecutune tcu unit. I have the svx side all figured out so here's my question if I put the stock 4eat in my legacy what am I going to have problems with? And what do I do for a tcu the stock one from my svx or from my legacy?
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Old 04-26-2011, 08:15 AM
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longassname longassname is offline
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Re: trans flip flop

The legacy and SVX TCUs are not compatible. You have to use an SVX TCU in a SVX and a Legacy TCU in a legacy. The problem problem is the TCU needs to match the gear ratio or else the vehicle speed calculated from the vehicle speed sensor 1 reading will be off. Vehicle speed is probably the most used variable in the TCU firmware right after throttle position. The car will drive with the calculated vehicle speed being off but most everything the TCU does will be off.

Maybe I can take a look at the legacy TCU in a couple weeks. I have two here: GJ marked as being from a 92 NA 2.2 and EV marked as being from a 91 turbo 2.2

Does the GJ match your car?

Last edited by longassname; 04-26-2011 at 08:18 AM.
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Old 04-26-2011, 08:53 AM
Subie-Addict Subie-Addict is offline
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Re: trans flip flop

Ill have to check the mark, specifically the Legacy is a 98 Gt limited with the na 2.5
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Old 04-26-2011, 09:03 AM
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longassname longassname is offline
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Re: trans flip flop

I'm sure that TCU is different. I'm leaving town for a couple days so let me give you a line to research in the mean time.

1)Find out if any earlier, obd1 model years have the same TCU your car has.
--failing that--
2)Find the page of the fsm for your car with the pinout of your tcu.
3)Find the page of the fsm for an OBD1 legacy with the pinout of its tcu.
4)mark any differences between the two, scan them if you have a scanner, and post them here.
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