CEL code P0768, valve body, solenoid - replacement help

[craigmcd]

Hi Subi Fans, 

I have a 2005 Outback, 3.0R VDC 5AT w sport shift.  Recently the CEL came on and produced code P0768, which has to do with the Shift Solenoid 'D' electrical. The solenoid is located on the control valve assembly, which is inside the transmission pan. The problem is intermittent, and I have been able to reset the code several times, but within a few miles the CEL comes on again. This last time while pulling a steady hill as it went to shift between 3 and 4. Until my next reset, it is stuck now in one of those gears. The sport shift would not work either. Of course, about half the lights on the dashboard are going wild, and cruise control is dead.

After much investigation I am pretty sure no one is re-manufacturing or rebuilding these valve bodies, and no solenoids can be purchased separately. 1) Does anybody know where I can get a rebuilt valve body with tested solenoids?

I have found a used transmission (131,000 miles) for $485, which includes shipping. 2) Is it a good idea to purchase a used transmission and then remove and reuse the valve body from it?

Subaru still sells the valve body under part #31705AA4309L, and those run $750 to $935. It is a new part and has at least some warranty. This valve body fits a good number of 6 cylinder 5AT Subi models from 2005 to 2007. 3) Is my best bet going to be a new valve body?

Last question. It is kind of a messy PITA job to get inside the tranny case just to look at the wiring and make sure things are plugged in, and replacing all the tranny fluid is not cheap. If I am opening it up I want to replace the valve body (or the D solenoid). 4) After replacement, does the car's computer need to be reset? Or can I just drive away? 5) If so, is that something I can do, or must the dealer (or my good independent garage) do it?

If anyone can help, or has any resources, please let me know - I am OPEN TO IDEAS. The car is great otherwise, but has a salvage title and 208K, so we are getting leery of big expenditures to keep it going. I have had it for eight years.

THANKS !!! Craig

 

[jonathan909]

Disclaimer:  I know nothing about ATs; the extent of my experience is replacing the 4EAT in my '99 Forester.  It was suffering from a neck-snapping 4-3 downshift under power - if you stepped on it for passing, to get power on a hill, etc., it felt like you were being rear-ended at speed.  No codes.  Xmission repair shop estimated $2400 (a nonstarter).  Found a matching transmission in a junkyard car; it had body damage (implying it was mechanically sound when taken off the road), so I took a flyer and spent $130 and an afternoon dropping it.  When I bolted it up it worked perfectly.

Having said that, if I were in your situation I'd get my butt to a (preferably self-serve) wrecking yard and pull a valve body.  Around here they charge $50 for them.

[craigmcd]

J909, thanks for the idea. I have been in contact with several salvage yards, and they are more than willing to sell me a whole tranny. To remove the valve body is basically to remove the heart of the thing, and completely devalues the remaining transaxle - so that has been a non starter. As I mentioned, I am considering buying a used tranny and then removing the control valves for my car. 

Today I spoke with my regular independent garage, the one I use for high level work, and he thought I should buy a new one from Subaru. So, unless someone can suggest a Remanufactured part, that is what I will most likely do. 

I am still not sure about the need to reprogram the computer. Any thoughts, anyone ?  Thanks.

 

[jonathan909]

I specified a self-serve yard because they're a completely different animal than a full-service yard.  They're utterly indifferent to the removal of the valve body devaluing the remainder of the tranny.  As far as they're concerned, any money they make on any portion of a car is gravy in advance of the rest going to the crusher for metal weight value.  I didn't pull that $50 (CDN) figure out of my butt; that's what they actually charge around here:

http://www.picknpull.com/part_pricing.aspx?LocationID=76&NavItem=12&SearchCriteria=&#partpricing

I'm not going to argue the point further - it's your money, spend it as you wish.  I just want you to understand that I'm not blowing smoke here.

On the reprogramming part, I don't know, but my guess is that it wouldn't be necessary.

Edited January 5, 2019 by jonathan909

[craigmcd]

Thanks again, I asked for advice and I value your response. Certainly not meaning to be argumentative. I used a pick-n-pull yard for a cruise control module for my van, and that worked out just fine.

To be honest, it has been very rainy here, and I don’t look forward to being under a car in a field draining transmission fluid (probably onto myself). In the garage it is not that big a deal. I will make a call or two tomorrow and see if my local yard has one. It is a good idea and a money saver.

[craigmcd]

It has been about a month and I want to follow up on this code P0768, and the replacement of the control valve body. The code shows the ‘D’ solenoid has some sort of error, it is either stuck open or closed, or not responding. The solenoid is an intragal part of the valve body and can not be purchased separately. I was not able to find any after market options other than used parts - there is nothing remanufactured. So, I ended up at my local Subaru dealer purchasing a brand new control valve body. These list at $956.00, but I was able to get it for $745.00 (by showing them a competitive price). This is a 5EAT in a 3.0 R Subaru VDC.

I have access to an automotive shop on an army base, so was able to do this repair with a hoist - which is a tremendous help. Step 1 - remove the negative battery terminal. After draining and removing the pan, I was staring at the valve body, which fills the entire cavity. Note: it took me a long time to clean the factory sealant off of the 21 small pan bolts - you should consider buying a new set. There was no gasket, only the Three Bond sealant. 

There are 13 bolts in two colors and two sizes which remove the valve body. You MUST keep track of them, and be sure to put them back in the same holes. The official repair manual shows the location and length of each of these screws, which is really important because they look just like other bolts on the VB that you should not loosen or remove. I used a cardboard box lid and made a diagram of the valve body, and put each bolt in a corresponding hole. There are three electrical connectors to remove the valve body, plus a fourth one which goes from one part of the valve to another. On this fourth one, it was NOT connected on the new valve body, so be sure to connect that. Take great care in unplugging these, do not pull on the wires at all - any damage to the wiring harness or connectors is a BIG problem. 

Once most of the ATF was done draining I was down to four bolts supporting it, one in each corner. At this point things were going well. I loosened the two bolts to the rear, then moved to the front. When I loosened the third screw the valve body dropped slightly, burped, and drained at least a 1/2 quart of fluid onto the floor from the rear (at least note down my shirt). So, pay attention to breaking that final seal, and have a wide pan ready to catch it. From this point on there was a constant drip of fluid, mostly from the rear area. 

I got help when it was time to fully remove all four screws. With one of us on each side we made sure to lower the VB straight down - then put it in a container to drain. After a final clean up of the pan, and the transmission surfaces, plus an inspection of the wiring harness, it was time to put in the new VB.

There is a mechanical shifting ‘slider’ which MUST be in the correct position. The open slot area on the shiny cylinder must mate with the shifting position linkage arm,  (the one which enters from the side of the tranny). I looked at the original, and noted the position. Then I moved it one or two positions, and then back again. You can feel the click as it engages each gear position. Then on the new VB, I made sure that the cylinder was in the same position, which should be for Park, since that is what the Subi was last engaged in. Failure to correctly position this, or to have the little arm come down and fit into the cylinder slot, will spoil your hard work. Triple check this !!!

So the two of us had four bolts ready, and lifted the new VB directly up into the cavity and inserted the bolts into the correct holes. Again be careful that these are the right holes. Be sure to get someone to help, the VB is slippery, a bit heavy, and costs $800-900 !  Put in the remaining bolts, but be careful not to over tighten initially. Finish off with the appropriate torque.

After that put on the pan with fresh transmission sealant, torque the little bolts, put a fresh crush washer on the plug, and prepare to fill with ATF. I saved the old fluid and measured it into a gallon jug. That showed I needed at least 6 quarts of fluid to get on the stick. Put the negative battery terminal back on.

Here is where Subaru has a big advantage. There is a procedure (see PDF) to BLEED the valve body before operating, but it requires the Subaru Select Monitor - which I don’t have. With the car off, but the key turned to Assesories (so the shifter will move), I went through each step of the procedure two full times. Taking plenty of time at each step. Then I checked the fluid, and added a little. Then I raised the tires off the ground, started the car, with no acceleration at all, gently went through each gear slowly a couple of times. I was trying for zero stress on the tranny while the fluid moved throughout the valve body. This whole procedure took about 20-30 minutes. With the car idling in Park, I checked the fluid again, and topped off until I got to the high spot of the cold mark. No CEL.

Time for a test drive. I took the car on a 1-2 mile gentle drive on flat surfaces, with as little stress as possible. Shifting seemed okay in 1,2 and 3. Then back into the garage for a final check on the fluid level, which seemed fine. So far so good. With my wife following in our other car, I drove it home about 12-15 miles, making 4th gear and 50 mph. After another more demanding test drive (5th gear and 65 mph), I noticed that the fluid was not even touching the end of the dipstick. I had to make a special trip (in another car) to Subaru for 2 more quarts of ATF-HP. It took almost a full quart to get back onto the dipstick and to the operating level. So the total was 7+ quarts. Yesterday I took the car on the interstate and went up one exit and back, about 17 miles. No CEL, normal operation. 

A note on shifting. It seems to take longer to shift into fourth, at a higher rpm. I think the same can be said of shifting to fifth. It is smooth through all upshifting. I notice more of a clunk in downshifting from 3 to 2, but not alarming. There is no other unusual thing to note. 

So, that’s my experience with this issue and the replacement procedure. There are some videos on YouTube, but they show the replacement on the bench, which is notably easier than under the car. Plan on throwing your cloths away after this repair. You will want a stack of clean rags and throw away gloves. This took me 5 to 5.5 hours. I also took my time and was very careful at each step. Cleaning the old pan bolts took about 45 minutes, maybe more. On the shade tree mechanic 1-10 (1 easy, 10 most difficult) scale, this is about a 7 or 8. Mostly because if you screw up any step with the VB, it is a very expensive screw up. Do NOT attempt to do this on dirt, any foriegn particles in the VB will ruin it. This was my first time inside a transmission.

If you don’t feel up to this repair, there is a lot to be said for the diagnostics and professional service of a Subaru dealer for this particular repair. I would imagine they would do this in 2.5 to 3 hours, and most likely will replace the pan and pan bolts rather then clean them. They have the special monitor, and will warranty not only the valve body, but also the work. If you go this route, but sure to check the ATF after a drive or two, and top off as needed.

I will try to include a pdf and a couple photos (which is not going well). The one chart lists the compatibility guide for my 2005 model. 

 

Control Valve Body 2005 Subaru.pdf

valve body 2005 Subaru 3.0 R.pdf

[GeneralDisorder]

Yep. We always replace the whole valve body. By the time one solenoid fails the rest are just as old. Half of them are on top of it anyway. This is also very common on the 10+ CVT's. 

GD

[craigmcd]

GD - every thing seems to be fine, in fact I drove the Subaru tonight on a 40 mile trip and it did great. I was concerned about not having the Subaru Select Monitor, but apparently it is not hyper critical. Do you use the SSM after installing the VB to bleeed the air.  Before doing tha job I read about resetting the computer, is that exactly what they were talking about? Also, is my guess if 2.5 to 3 hours for a dealer or experienced shop about right ? I spoke to my regular independent garage who have done a few things for me, and they were not real fired up to replace this particular part. They are Subaru / Japanese guys.

[GeneralDisorder]

It's closer to 3-4 hours.

I don't use the SSM or anything like that. We just fill them up, run them through all their gears on the lift, check the fluid and drive them. Never had an issue. 

GD

[craigmcd]

Thanks GD - that gives me more confidence. My wife took the car to work today, 40 minutes on the Interstate.

Here are the photos I promised with a couple of notations.

[Mike104]

That looks like a fun job to do on the ground!  Good thing you had a lift available

[craigmcd]

It has been just about 2 months since I did this VB replacement, so I thought I would follow up. Everything is working perfectly! No CEL or other issues. No leaks, no loss of fluid. The car has been on several longer interstate trips now with no problems. The rough shifting I noted above seems to have settled down, or else I have gotten used to the new norm (it is hard to tell). Glad this went well.

PS: Definitely do NOT do this job on dirt. Cleanliness is essential.