Duty Solenoid C
 

My mechanic and I just did a 4.44 swap on a ’92 using a 1998 Forester transmission. It’s the second 4.44 swap we’ve done and the first one has worked just fine for over a year now. With the second one, though, it’s binding a bit. It’s most noticeable when turning sharply at low speed. I’m getting a Transmission Code 24 – Duty Solenoid C code.

My mechanic took the car back into his shop and pulled the transmission pan. The filter had been rubbing against the bottom of the pan because the pan must have been hit and bent up when the donor car was totaled. He fixed that and replaced the Duty Solenoid C with a new one. But I’m still having the same problem.

I'm hoping to give this car to my sister who lives 2,500 miles away. She'll be here in less than a week so I need to fix this problem right away.

Any ideas?

Re: Duty Solenoid C
 

If you still have the old trans you could just pull the whole rear section and swap it. Other than that I am not sure, you may need to search out some of the threads on binding. I think they walk through how to verify if it is the solenoid or something else though depending on if it binds with the 2WD fuse in. Been a while since I looked at them. Sorry I don't have better detailed info or suggestions.

Re: Duty Solenoid C
 

Does binding go away with FWD fuse installed?

Re: Duty Solenoid C
 

Knowing nothing about solenoid C, I would be real anxious to learn the relevancy of the above message to the fore named problem.

Thanks,
Keith:cool:

Re: Duty Solenoid C
 

Keith, As there is no Code for a C solenoid problem, it has to be assumed that the solenoid itself is OK, but the transfer valve, or the clutch is at fault.
The point of doing this, is that if the binding goes away by inserting the fuse, it means that the clutch pack is not the problem. It can be some other problem, like a speed sensor, or the mix of two different speed signals from the two different diff ratio signals, due to the 4.44 swap.

Harvey.

Re: Duty Solenoid C
 

Does "having of the same problem" include getting a code 24?

If you are still registering a code 24, there could be a wiring or connector fault.

You refer only to the removal of the pan which would not give access solenoid C. Did your mechanic remove the rear assembly? Could he have replaced the wrong solenoid?:confused:

Re: Duty Solenoid C
 

Thanks for the suggestions. To clarify:

1. “having the same problem” does include still getting a code 24 and still binding;
2. there is no chance that Duty Solonoid C was not replaced. The mechanic did remove the rear extension of the transmission to replace it.

Since my initial post I inserted the FWD fuse. With the fuse installed I don’t get any binding and I don’t get the code 24.

Now what?

Re: Duty Solenoid C
 

The situation is difficult to logically explain. The solenoid valve C is normally closed, so that when not energised full line pressure results in a closed centre clutch and binding. When energised as result of inserting the fuse, the valve is opened thus reducing pressure and releasing the centre clutch, i.e. a logical and normal outcome.

This then makes the TCU or associated inputs/sensors and circuits suspect. But why no relevant codes? However it does appear that the TCU is not providing proper control and opening of solenoid valve C.

In view of the transmission change, connectors and wiring must be suspect.;)

Re: Duty Solenoid C
 

Altogether too often in these threads a person asks for help with a problem and the thread just peters out with no indication if the problem has been resolved and if resolved, what the resolution was.

I'm pleased to say that my problem has been resolved. It was a defective TCU. I happened to have a spare one in my garage and after I plugged it in and test drove with it in, there was no more indication of any stored trouble code and the binding has stopped.

Once again, I thank those who took the time and effort to respond. This site is a very valuable resource to me and it's you guys who make it so.

Re: Duty Solenoid C
 

That's amazing!,

Amazing that a TCU was the problem, as I have never heard of a TCU being a problem :eek:

Amazing that you had a spare to test and solved the problem :)

Were the TCUs the same, with the same BIG letters?

Thanks for posting your success,
Ron

Re: Duty Solenoid C
 

I didn't think it was the TCU either since they don't seem to be problematic. I think a few people here have had TCU problems but not very many for sure.

I've had done two 5-speed swaps so I had two spare TCUs in the garage. Now I have only one. And they are the same, with the same letters. I almost didn't keep either one of them since I didn't think I'd ever have use for them. I'm glad I didn't chuck them now tho.

Re: Duty Solenoid C
 

Thanks for advising on the positive outcome. Although confusing, as I explained, based on analysis and logic, the issue certainly pointed to the TCU. ;)

Re: Duty Solenoid C
 

That was a tough one, Trevor!

I am sincerely impressed.

Cheers,
Keith:cool: