Searched. Found nothing. Duty Solenoid B

[Gnuman]

92 Legacy sedan AWD 4EAT 160K miles EJ22. Recently replaced engine as camshafts in the old one siezed after the heads were surfaced. Flashing Power light, so I did the TCU dance to get the codes. Got only one for existing as well as previous: 12 Duty Solenoid B. Did a search in this forum for Duty Solenoid B and got a lot of description on how to get the codes (thanks) and what they mean, but nothing on what Duty B does, or how to replace it if needed. More info below:

 

Transmission seems to shift fine.

Torque Bind is NOT evident.

No noticable problems with transmission operation

Speedo acts strangely (intermitantly): displays 2x speed. (this only happens when just starting. Goes away after a few moments)

Nothing done to transmission during engine swap. Connectors not touched at that time at all. Did check that they were tight when the speedo problem was noticed.

 

OK, Transmission Gurus, What'cha got for me?

[Andyjo]

If i remember right, there IS a Duty Solenoid B... what it does..well that you can leave up to your imagination. :-p

It's location... i believe it's in the middle half of the tranny, not so accessible when it's in the car :-\

maybe the code reader is confused?

are you sure you're getting power to the rear wheels?

[Gnuman]

I'm pretty sure, yes. When I punch it, I do not break traction. If all of the power was going to the front, I would peel big time. I know. I had to drive an Outback that had the driveshaft pulled. Got stuck in a spot that I had to punch it to change lanes. . . the front tires did not stop spinning until I let off of the gas as it was drifting to the side. . .

[OB99W]

[...]Flashing Power light, so I did the TCU dance to get the codes. Got only one for existing as well as previous: 12 Duty Solenoid B. [...]

 

Transmission seems to shift fine.

Torque Bind is NOT evident.

No noticable problems with transmission operation

Speedo acts strangely (intermitantly): displays 2x speed.[...]

This may help: http://endwrench.com/pdf/feb2004pdf/4EAT.pdf .

 

See page 10 for the location of Duty Solenoid B and what its function is. See page 12 for what happens if a particular solenoid fails (for DS B, it's that the torque converter won't lock up, which might not be immediately noticeable).

 

I realize that a '92 isn't equipped with OBD-II; however, do read the "OBD-II Purpose" section of the PDF on page 14, as it covers earlier diagnostics and operation as well. It explains the relationship between DS B operation, torque converter lockup, engine speed versus output shaft speed monitoring by speed sensor (#1), and ECU/TCU interaction.

 

I suspect that the speedo problem is related to the trans one. If the ECU gets what seems to be wrong data from one of the Vehicle Speed Sensors (either because the data is wrong or because the ECU has a problem), it will ignore that and use info from the other VSS. The 2x speedo reading that quickly goes away may point to that happening.

 

When the engine got swapped, did the ECU or its wiring possibly get changed or disturbed?

 

EDIT: VSS info is on page 5, but the entire PDF is really worth reading.

[Gnuman]

This may help: http://endwrench.com/pdf/feb2004pdf/4EAT.pdf .

 

 

I suspect that the speedo problem is related to the trans one. If the ECU gets what seems to be wrong data from one of the Vehicle Speed Sensors (either because the data is wrong or because the ECU has a problem), it will ignore that and use info from the other VSS. The 2x speedo reading that quickly goes away may point to that happening.

 

 

that would make more sense except that the speedo is cable driven from the tranny. Later cars went to an electrical one, which would behave exactly as you describe. Duty B has been ordered, and will be installed when it arrives.