91 Sedan 4eat only has 3rd, reverse, and park.

Flywheel, Clutch, Transmission, Axles, etc...

Moderators: Helpinators, Moderators

Post Reply
Bishop
In Neutral
Posts: 11
Joined: Thu Nov 14, 2013 9:07 am
Location: Salem, OR

91 Sedan 4eat only has 3rd, reverse, and park.

Post by Bishop »

Hello everyone, as the title says I am working on a 1991 Legacy LSi sedan with 4eat. I've done an engine swap with a 2.5 frankenmotor which was an adventure of its own, ending up with a haltech elite 550 and cleaned up wiring harness. The engine runs great but needs a little dyno time to get the ignition curve down which brings us to the current issue, the transmission only has park, reverse, neutral, and 3rd gear no matter what position the selector is in or if the manual button is engaged. The tcu is giving us the 16 flashes but will not output any codes after performing the secret handshake multiple times or when trying 2 different tcu's, one from a 93 fwd and one from a 95 impreza awd.

Any input would be appreciated, Thanks!
arse_sidewards
First Gear
Posts: 107
Joined: Thu Jul 21, 2016 12:17 pm

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by arse_sidewards »

It has detected an electrical fault and put itself into what's basically limp mode, or the TCU can't even reach the trans.

You have three options, harness problem, connector problem or solenoids. My money would normally be on solenoids, mostly because these cars aren't known for harness problems and there's a reason Subaru put a filter on later iterations of that trans, but since you've just done an engine swap I think connectors or some incompatibility there like that is more likely. Maybe take a look at what you did to "clean" up the harness.

FYI it's perfectly safe to drive other than the poor acceleration and doing 4000rpm at 75mph not being ideal for the engine.
'93, '93 and '94 Legacy L, wagons, FWD and AWD, all are NA 2.2 w/ 4EAT.
Bishop
In Neutral
Posts: 11
Joined: Thu Nov 14, 2013 9:07 am
Location: Salem, OR

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by Bishop »

Thank you for your reply, the bit of harness that was cleaned up should have just been the engine sub harness, we found the cam and crank position sensor section to be damaged and repaired it. On the ECU side we depend the factory ECU plugs and put them into the haltech plug. I will let the shop know to continue checking for solenoid or transmission harness issues.
Bishop
In Neutral
Posts: 11
Joined: Thu Nov 14, 2013 9:07 am
Location: Salem, OR

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by Bishop »

I believe the center diff is also binding up due to this, with that and the tuner not being comfortable really working the car on the dyno we're hesitant to drive it on the street.
Legacy777
Site Admin
Site Admin
Posts: 27912
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by Legacy777 »

So you've followed both procedures noted on my site to try and get codes from the TCU and still just get the 16 flashes?

https://www.surrealmirage.com/subaru/trans.html

Does the shop have the wiring diagrams to trace each circuit that is noted by the codes? That would be my first step if I was unable to get the TCU to give me its error codes.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
arse_sidewards
First Gear
Posts: 107
Joined: Thu Jul 21, 2016 12:17 pm

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by arse_sidewards »

I would find the pinout for the harness connectors on top of the trans and then probe them accordingly with 12v and ground if necessary in order to verify solenoid operation. The solenoids are loud enough to hear with the engine off.

I think you'll likely find that everything on the trans side is good and that some oversight in the engine bay is the source of your problem.
'93, '93 and '94 Legacy L, wagons, FWD and AWD, all are NA 2.2 w/ 4EAT.
Bishop
In Neutral
Posts: 11
Joined: Thu Nov 14, 2013 9:07 am
Location: Salem, OR

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by Bishop »

Resolved, the main transmission plug had a few pins come loose when the previous owner swapped it.
Legacy777
Site Admin
Site Admin
Posts: 27912
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: 91 Sedan 4eat only has 3rd, reverse, and park.

Post by Legacy777 »

Glad you got it sorted and it was an easy fix.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Post Reply