legacycentral bbs

Hello everybody I have been a long time reader just never posted up till now.
Anyways I have a 1992 Legacy Non Turbo with 278k on the clock. A few weeks ago I was getting ready to leave work so I fired her up and let her warm up (like i always do) hopped in it and saw the power light was on, I didn't think much of it cause it has the center diff issues just like almost everybody else. So I took off thinking it was nothing, well i took a left hand turn and the car started to feel like it was trying to shift really hard a lot of times so i looked at my dash and saw the power light freaking out and the atf light flashing. I flipped around and went back to work, by the time i made it back it was starting to slip bad and making loud banging sounds. I called up the wife and had her pick me up.

The next day I took a look at it. Trans fluid was still red and didn't smell bad. The front diff was great too! I tried to pull the codes but it wouldn't go into diag mode. I then tried to drive it a bit and found that it would go into reverse but if i tried to turn it would bind REALLY BAD, all forward gears would slip. I also found that if i put it into drive and just sat there it would stall its self.

After all that I decided to toss another trans at it, I found a low millage 93 so i grabbed it up. Well yesterday i put it in, Added all new subaru fluid and changed the filter for good measure. Well its still doing all the same things as before!! at this point it was 1130 at night so i just left. This morning i pulled the #14 fuse and let it sit for a while, then disconnected the battery for a while. Fired it up and still no luck. The power light blinks with no pattern and the atf light flickers a little. Once again I tired to pull the codes and it will not go into diag mode, i must have tried it 40 times thinking i was doing it wrong.

What else is there to replace other than the TCM? Should I toss a new TCM in it and see if that works? I'm really at a loss on what to do next. Any help would be grateful!!

Thanks in advance Guys

looks like the TCU is ur best option... coincidentally i have one i need to take out of my parts car lol

Someperson wrote:looks like the TCU is ur best option... coincidentally i have one i need to take out of my parts car lol

Where actually is the TCU located?

Has anyone else run into the same situation as me??

Could possibly be a rear end issue. Try inserting a 15 amp fuse into the FWD slot (passenger side of the engine bay, near the firewall & strut), and see if that makes any difference. If FWD mode decreases slipping, i would suspect rear end. Not sure if that could cause the Power and ATF lights, but just a thought. IIRC the TCU was underneath the driver's dash, toward the center. It was a gold housing in mine, as opposed to the silver ECU. I also have an extra one sitting in my trunk left over from the swap if you end up needing one.

Hi,
TCU is under driver's side panel, near the steering column - 2 10mm nuts hold it up there.

After trying the FWD fuse, I'd disconnect the rear drive shaft @ the front of the rear diff - 4 12mm nuts/bolts to undo (this is how I tow Subies w/the front wheels on the tow dolly and rears on the road - no issues after doing this 5-6 times).That removes the trans from the equation.

Drive it and see if the power/atf lights still have issues, the 'binding will still occur, I'd bet.

EDIT: Sounds electrical -

Your '92 has a 3.90 FD ratio. You'll need a diff from a '92-94 Legacy AT -NA or Turbo- or a '93-97 (?) Impreza 5-speed (check the pinion flange on the Impreza - Subaru changed bolt patterns somewhere in the '90's).



GL,
TD

Here is a picture of the ECU & TCU

http://www.main.experiencetherave.com/s ... cuhide.jpg

When you said the power light blinks without any steady pattern, do you mean it blinks constantly, or it's very random. If so, and based on what you described, I think the issue is electrical related and could be wiring and/or a bad TCU. The rear diff issues others have mentioned would not cause the weirdness you are seeing with the power & atf warning lights.

Replacing the TCU would be the least time intensive option. Checking and tracing all the TCU related wiring would take much more time, but wouldn't really cost you anything if you have a good multi meter. If you can find a decent deal on a TCU, that may be the easiest option to explore first.

I have tried the fwd fuse both with the old trans and new trans, both times with no luck. The lights blink very randomly and start doing so with key on engine off so im almost 100% positive its electrical. The rear diff fluid is
perfect ( redline shockproof)

I will pull the tcm today. Thanks for the advice/help!! Ill keep everybody updated

What year of tcm would work with my car? I was dumb and didn't pull it and the junkyard needs the numbers off it. Is there more than one kind for a 92

No idea? Check the drivetrain board or electrical board

Yes, there is more than one part # for the 92. What is the part # on your TCM? Any of these 92 TCM's "should" be compatible with each other

31711AB352
31711AB353
31711AB354
31711AB355

If you have either 353, 354, or 355 I'd suggest trying to find one of those, as they all supercede to 355. 352 does not supercede, but "probably" would work in a pinch.

Ok so mine is a 31711ab354

Looks like it got a bit hot...

Does anyone elses look like this?

Legacy777 wrote:Yes, there is more than one part # for the 92. What is the part # on your TCM? Any of these 92 TCM's "should" be compatible with each other

31711AB352
31711AB353
31711AB354
31711AB355

If you have either 353, 354, or 355 I'd suggest trying to find one of those, as they all supercede to 355. 352 does not supercede, but "probably" would work in a pinch.

I just found and ordered a 355 one. Thanks for the info!!

That's normally how they look.

Well im happy to report that the tcu fixed it. Thanks for all the help guys!!

Good deal, glad a new TCU fixed the issue.

no prob, glad to help

Well i blew another one!!! I was going home and i heard some rattling that only would happen under load, two miles later i was pushing it through an intersection!! I have had it with these automatics!! So i picked up a parts car with a 5speed!! Yesterday i pulled the engine, trans, front axles, driveline, rear diff and pedals. What all else will i need bare minimum to get my car back?

Clutch, pressure plate, clutch master cylinder

Master cylinder? I don't think a cable clutch has that...right? Also the parts car was a wagon, any differences to my sedan?

Oh, it's a NA setup? Nvm on the mc then... Trans mount from the 5mt car

I don't need any electrical items in order to get it up and going?

Hi,
Check JC's 5-speed swap thread HERE.

I didn't bother w/the starter interrupt (clutch engaged to start).

GL,
Td

So pretty much what i do is remove the tcm and shift lock, cut a wire on my ecm harness, cut the neutral safety harness off the donor car and wire it into the harness on my car and im good right? Any help with the wiring aspect of this would be great, im not too savvy with that

Hi,
Please read the entire JC's swap info in link above. Reply back w/specific questions.

I struggled w/the wiring too, so I understand, but it helped a LOT to read it thru a couple of times. Do a 'virtual' swap in your head to think thru it.

GL,
TD