[rrutherf]

2001 Legacy GT Wagon, 2.5L, 4EAT, 100000miles, no mods.

Firstly: thanks to all those who made the head gasket, water pump, pulleys,timing belt swap so understandable - Keyoutback, Subiesailor and so on.
Engine is back in and running well. Problem is with the automatic which was perfect before the engine removal/replace but is now throwing codes.

Check Engine light: ODB2 gives P0778 (Solenoid B). Comes back after being cleared using ODB2 scanner.
AT Fluid Hot light: TCU gives either 76 (2-4 Brake Duty Solenoid) or 77 (Lock-up Duty Solenoid. Comes back after being cleared by pulling Fuse#4.

Lost a little fluid when disconnecting AT lines from Rad - added about 6 ounces of Dexron to bring it up.
Slightly concaved the AT pan when lifting for engine alignment (My Bad).
All related electrical connectors have been separated, treated with Dielectric grease and reconnected.

System is now in limp mode with no 1,2 3 - only Drive. Low speed disconnect of AWD is not functioning - scuffs on tight turns while parking.
Starting voltage and continuity tests of harness from AT to TCU but progress is slow.
Is it possible the concaved pan is shorting/grounding the solenoid connectors?

 

[RobLog]

All related electrical connectors have been separated, treated with Dielectric grease and reconnected.

It's alright to use dielectric grease on the nonconductive rubber or plastic mating surfaces of connectors, but if you get it on the connector electrical pins, it can interfere with the electrical signals passing through the connector and cause problems such as those you've been experiencing. If this is what happened, you need to clean the grease off the pins.

Slightly concaved the AT pan when lifting for engine alignment

Dents in the pan have known to cause P07xx errors due to sensor wires being broken or insulation being cracked or a sensor itself being cracked.

 

[rrutherf]

Roblog. Thanks for the input. I felt that there was enough spring force in the contacts to allow the grease but I will clean with mineral spirits and try again.
I will also drop the pan to straighten it and will check all internal wiring at that time.

 

[idosubaru]

what he said - i'd clean the pins first then if that doesn't help anything, check the pan.

you could entertain checking for continuity to track down the issue. if you have bad continuity at the transmission connector then you know the issue is probably inside the transmission and related to the pan incident.

 

[rrutherf]

Grossgary: glad you concur and the pan has to be straightened anyway.- also gives me a chance to change the fluid.

 

[modenaf1]

What ever happened with this? I have the exact same thing. Removed motor, slightly concaved pan jacking the tranny up. What ended up being the cause in your case?

 

[idosubaru]

What ever happened with this? I have the exact same thing. Removed motor, slightly concaved pan jacking the tranny up. What ended up being the cause in your case?

it's really easy to fix - just pull the pan and replace the damaged solenoids. very simple. a bunch of 10mm bolts to remove pan - pull offending solenoids. i've repaired 00-04 transmissions before, the solenoids are weak at the wiring connector and just crack off. failure is almost unheard of, i wouldn't buy new ones from Subaru - they're pricey.

 

[modenaf1]

Yup that was it - when I dented the pan I cracked a connector off of the 4-6 braking solenoid with the red connector. This one looks to be mm away from the bottom of the pan and a bit lower than the others. I had the same code as the OP. It's cracked in such a way that I couldn't solder it and have to get the car running by tonight, so I just bit the bullet and got a new solenoid and pan from Subaru. It was like $300. OUCH!


I'll post back with the results after work tonight - I'm just glad I found something that was actually broken and fixable.

 

[modenaf1]

Yup that was it - when I dented the pan I cracked a connector off of the 4-6 braking solenoid with the red connector. This one looks to be mm away from the bottom of the pan and a bit lower than the others. I had the same code as the OP. It's cracked in such a way that I couldn't solder it and have to get the car running by tonight, so I just bit the bullet and got a new solenoid and pan from Subaru. It was like $300. OUCH!


I'll post back with the results after work tonight - I'm just glad I found something that was actually broken and fixable.

That did it. She's working great! That one solenoid connector is right where the pan has a bit of a divot in it, as well as the magnet so there is pretty much zero clearance. Don't dent it! Luckily easy enough fix.