Electrical or Transmission induced TCU codes??

[Svx95]

Exactly 20 days ago my car sat for 2 days while I dynamatted the entire trunk, rear deck, rear quarter panels,floor, and the doors. I also went ahead and sprayed Rustoleum undercoating on the undercarriage in preparation for winter as some of the OEM protection was missing. I had to let that dry for a whole day hence why the car sat for 2 I put everything back together and drove the car to work the next day all was fine. On the way back from work I had very hard shifts (shift shock) and ocassional flares on the 3-2 downshift and overall driveability was horrible. I pulled TCU codes 11, 12, 13 and 25. This is a 4.44 swapped car with QC and ECUTUNE 4.44 TCU. Ignore code 25 as that is caused by the QC. So the troubleshooting journey began.

I tested the Dropping resistor behind the battery and that was fine at 12.6 Ohms iirc. Next was TPS, which also tested fine, no dead spots or erratic voltage sweeps. Set at .48v. Tried adjusting it to .50 but only made things A LOT worse so set it back to .48v. I also checked the plugs to the transmission they were both securely fastened and no bare wires or fried for that matter.

I became suspicious of my modifications so I tested the QC and that was normal. I swapped the ECUTUNE 4.44 TCU with the stock 3.54 TCU and the problems remained.

I was informed to check grounds. So I did, and I found a fried wire going from the firewall to the pitch stop mount. I replaced it with 4 AWG wire and tested. Being hopeful but no luck. I got codes 11, 13 and 25. Since this wire was replaced I have not had code 12 reappear.

While I was in the whole wiring aspect of things I performed the wiring configuration_V4 following John Hoffman's How-to PDF. I also replaced the main ground lead from the negative terminal of the battery that attaches to the bellhousing of the transmission. I coated everything with dielectric grease and made sure the connections were solid. I got codes 13 and 25.

I was happy yet frustrated, all the time and money and still no reliable svx! Who am I kidding, that is not a realistic statement when you own an svx.

Anyway the problem(s) that remained as of 2 nights ago were only codes 13 and 25 and realistically only code 13 as the latter is caused by the QC. However, driving back from work today I got very harsh shift shock and what I feared proved true. Code 11 was back along with 13 and 25.

To add to the mystery the codes are present even if I clear the codes by pulling fuse 14. Heck, I even went ahead and unplugged the battery overnight to reset everything and the codes came up on the first startup. The codes are supposed to appear after a test drive not before. Hence the inclination towards an electrical problem. I know the codes are triggered by either a short, an open-circuit, or stuck solenoid.

What am I supposed to do know? I am honestly at a loss of ideas. The only thing I haven't done is drain and refill the transmission. Should I?
The fluid level is good, still bright red. It was changed around 5,000 miles ago, drained not flushed.

Any ideas are greatly appreciated, thanks!

[Chucksta]

Code 11, the "A" solenoid responsible for shift line pressure.. Gee, that's sounds very, very familiar. Mine started acting up out of the blue, no reason that I could see. I had actually just changed out 4 liters of full synthetic and a new filter. If it was stuck, it was usually stuck right from a cold start. A restart would cure it until it cooled completely, which led me to believe, ( or at least hope ) that it was the valve itself that was sticking, and that the issue wasn't electrical in nature. I priced out replacing the valve, and decided that there wasn't much harm in a "Hail Mary"...

I'm not much of a believer in "snake oil", but I dumped in Lubegard Platinum

http://www.lubegard.com/~/C-113/LUBE...ATF+Protectant

The main thing about it was that it claimed "frees sticky valves and keeps them free"

Within a week, the "A" solenoid was a happy camper once again. Almost 8 months later, it's never malfunctioned.

Yeah, I got lucky. Obviously, if your issues are electrical in nature, it won't help, but for less than $20.00, it probably can't hurt.

good luck.

[Chucksta]

Well ... talk about not opening your mouth ... Started her up at 6 C, and did I not get the solenoid "A" , jammed in the full on shift experience.. shifted like it was being hit from behind with a hammer. If it would have been a two wheel drive vehicle, it would've chirped every shift. .. It shifted like a really, really, really big hammer was smacking it in the ass. I did what I did before, tossed it into neutral, turned it off, turned it back on, and it went back to normal. Immediately.As before, the symptom didn't return for the rest of the ride home. If it repeats, I'll change the filter, change out four litres of synthetic, toss in another dose of lubegard platinum and see if it goes away again. If it does, fine.. If it doesn't, and continues like this, I'm not going to dick around with it. I've got a spare transmission with 12K on a $3,700.00 factory Subaru rebuild. I'll just swap it and keep the current one for a core. GRRRR....

I'll post how it goes either way. If I land up swapping it out, I'll pull the "A" solenoid and see what made it stick, if anything is visible or whatever..

Had to open my mouth about the "Lubegard fix" , now didn't I.. Only upside to this is that I know how to make it stop, until I can deal with it.. When I had an issue with it last time, it never happened while driving. It was either off the start, or not at all. It never presented itself on a warm restart. That's what led me to believe it was an internal issue with the solenoid itself, not an electrical fault.

As a side note, there was a shift kit installed when I got the car. I didn't like the way it functioned ( either on or off, no in between ), so I swapped it out and put in a "Quick Change".. That performed much better, there was only one glitch that I ever noticed. If I put the shifter in 3rd, and pushed the "manual" button, that should have limited the transmission to second gear only, which was what I wanted. But, if I stood on it, it would fall on it's face as it passed through the speed at which it would've normally shifted from first to second at WOT, the point at which the factory TCU would've pulled back the timing and injector bandwith to comply with the factory shift protocol. That would seem to imply that, no matter what shift kit or programming is used, it will still address the solenoid "A" function, but I don't know if that's relevant in this scenario.

[Blacky]

Chucksta where do you get lubegard platinum in Canada?

[Svx95]

No way! Sorry to hear that. Yeah, the way you describe the shifts is right on point. The first time shift shock happened I tought the f250 driving behind me had rear-ended me!

That was going to be my next step, drain, change filter and refill and add the lubegard. This transmission is fairly "NEW" I did the 4.44 swap less than 6,000 miles ago. So it better not die on me!
Ok, sounds good. Please do and post pictures of it if you can! Thanks for keeping me in the loop.

Interesting that yours happens now while driving it too. My Code 11 (Solenoid A) can come an go multiple times a day or it won't be present for a couple of days and then BAM it's back. There is no difference in the car being cold or warm or 1st drive or 8th drive of the day.

*Answering your side note: The car must have came with the smallcar shift kit which is not as good as the QC because like you said the it was either full on or full off. The QC only performs its function in the "D" position so once you shift into "3", "2", and "1" the TCU regains full control without taking input from the QC.

[Svx95]

As of today I only have codes 13 (shift solenoid 3), and 25 (Torque Converter). 25 is caused by QC so don't pay attention to it

Grr. I just want my car to have awesome driveability like it did 24 days ago!

[Chucksta]

LubeGard Platinum is available at Canadian Tire..

http://www.canadiantire.ca/en/pdp/lu...l#.VEiyliLF9Zg

If they don'y have it in stock at your location, they will order it for you. If they don't have any in stock, ask at the service counter if they have any. They may have a few on hand for the shop that don't show up in inventory. Gee, That says something, doesn't it?

Mine hasn't done it again since I mentioned it. I think she was just a bit pissed that I let her secret out LOL.. We shall see what happens and go from there. I checked to make sure “power mode” was functioning correctly, and it was. Then I engaged warp drive, and it shifted like a champ, and it hasn't glitched since.

There were a couple of other subtle changes from adding the LubeGard.. I used to get a “mystery bump” occasionally when stopped when the trans wasn't yet fully warmed up. It felt like a pedestrian had walked into the back of the the car... That has stopped. The first to second shift was abrupt, I've read that that was common after a rebuild, due to a difference in friction material used. That has abated, the shifts are now crisp, but not harsh. Probably the effects of the friction modifiers and seal conditioners in the product, or just dumb luck.

@ SVX95.. Thanks for the explanation of the QC only functioning in “drive” .. I'd written that off as being an idiosyncrasy of aged electronics. The TCU and the ECU decide between them whats what with drive train management. I was just surprised that the engine was pulled back at a shift point where thee wasn't a shift occurring.. Also, as I've had a long term issue with the torque converter not holding lock up with the cruise on, I didn't know where to put the blame for that one. The cruise control changes the shift parameters of the trans, but shouldn't act like that. As no other QC users have had that issue, I'll just write that off as aging electronics having a small hissy fit. If I get ambitious, I'll look up which wire sends the “cruise is on” signal to the TCU, and just clip it.

When you say you aren't getting the codes consistently, ( as in code 11 ), Hmmm.. if I recall correctly, the codes fall out of current retrieval if the issue doesn't replicate for three or four starts. If you're using a code reader, they'll show as stored or previous, but, it you're counting the flashes on the ATF light on the dash, it's a different sequence of shifter positions and manual button clicks to retrieve previous codes. as opposed to current ( within the last few starts). The retrieval process for the two different retrieval methods is a PITA, but will only tell you if the issue is a few starts behind you.

[Svx95]

Originally Posted by Chucksta

When you say you aren't getting the codes consistently, ( as in code 11 ), Hmmm.. if I recall correctly, the codes fall out of current retrieval if the issue doesn't replicate for three or four starts. If you're using a code reader, they'll show as stored or previous, but, it you're counting the flashes on the ATF light on the dash, it's a different sequence of shifter positions and manual button clicks to retrieve previous codes. as opposed to current ( within the last few starts). The retrieval process for the two different retrieval methods is a PITA, but will only tell you if the issue is a few starts behind you.

My vehicle is a '95, therefore I count POWER light flashes. I believe '96 and 97's use the ATF light. I use the gear lever sequence for current codes during retrieval.(I personally think it is very easy, takes no more than 20 seconds to have codes displayed). To retrieve "OLD" codes you perform the gear lever sequence in reverse order starting on "1" instead of "D". Once I have the codes I reset the TCU code memory by pulling fuse #14 for at least 1 min.

[Svx95]

After further inspection/troubleshooting,with the guidance of Harvey (OAB_AU), I have tested the resitance from all the solenoids in the transmission without having to drop the pan and valve body of the transmission.

The US and AUS plug are a little different due to ACT-4 vs VTD, but the differences don't affect pin location/wire color. The plug coming from the left side (drivers side) of the transmission is a 16 pin type. However only 13 pins are utilized for the US vs 14 pins for AUS.

TCU 16 pin plug

Notice: The plug’s head on. Therefore the Pin # is addressed right to left.

US: Act-4
Pin Wire color Function Reading (Ohm) Specs (Ohm)
1 Light blue Shift Sol 3 24 20-30
2 Green Shift Sol 2 24 20-30
3 Yellow Shift Sol 1 26 20-30
4 Black(Thin) Ground Ground Ground
5 White ATF Temp ATF Temp ATF Temp
6 Blue Duty Sol B 12 9-15
7 Red Duty Sol A 2 1.5-4.5
8 Black(Thick) Ground Ground Ground
9 White/Red stripe Speed Sensor 1 -- --
10 Black/Yellow stripe Speed Sensor Shield-- --
11 Brown Duty Sol C 11 11-15
12 Orange ATF Temp Sensor -- --
13 Yellow/Green stripe Speed Sensor 2 --
14 Absent -- -- --
15 Absent -- -- --
16 Absent -- -- --


So all the solenoids were within spec. It makes me think the solenoid is faulty when in motion.

[longassname]

A transmission repair shop is able to get the solenoid pack from their transmission parts distributor for significantly less than they cost from the dealer. I would get an OE pan gasket from the dealership and take your car to a transmission shop for quotes for replacing the solenoid pack.

They only have to drop the pan and the valve body to replace the solenoids.

[Svx95]

Originally Posted by longassname

A transmission repair shop is able to get the solenoid pack from their transmission parts distributor for significantly less than they cost from the dealer. I would get an OE pan gasket from the dealership and take your car to a transmission shop for quotes for replacing the solenoid pack.

They only have to drop the pan and the valve body to replace the solenoids.

Thanks for the info, I have (since my last post) replaced the solenoids from that of a spare legacy transmission. I dropped the valve body myself, just followed the FSM it wasn't complicated at all. The problem remains, with a code for shift solenoid 3, which causes braking once I let off the gas. I don't know if my band wore out but I don't notice any unusual driveability. I have cleared the code, or at least attempted to numerous times. However, the POWER light flashes upon first startup regardless of driving the car or not.

[Chucksta]

So.. I found a problem..

Earlier I posted that the trans was pulling a "solenoid A" fault code and I was going to swap out the transmission for my recently factory rebuilt spare. So I do that, and damn if I don't, within a week, get the "Solenoid A" again. WTF. I drove this transmission a year ago, before I bought the vehicle as a parts car. There were no codes when it was delivered. Now it's doing the same thing as the trans I just pulled.

Common denominators..

Started having issues when it got below 0 C .When it was cold, it would have an "A Solenoid " issue on first start, it would be fine after a warm restart, and function normally until cooled overnight to below 0C

When I swapped in the rebuilt one, I swapped the TCU with it. I couldn't believe that the same problem was not electrical in nature. So, I disconnected the quick change. Haven't seen a fault code since. The trans shifts fine, so I've got to wonder if I even had to pull the old one out.

The common denominator, the only thing that was the same, that spoke to the ECU and TCU... the Quick Change..

I have several theories, but no way to check them out.

1) I somehow damaged the Quick Change during installation.
2) For some reason, the Quick Change is affected by low temperature
3) The Quick Change sends the A solenoid too far towards full line pressure and the increased viscosity due to low ambient temperature is incompatible with it's use.

So for now, the Quick Change is not in the circuit.

Also, after it was initially installed was when I began to experience an issue with the torque converter unlocking intermittently at highway speeds, but ONLY when using cruise control. I couldn't diagnose why, but wrote it off to an aging TCU, as there is a different shift mapping when cruise control is engaged, although I haven't been able to find out if that's true if cruise is on, or only if engaged. But I had the same issue even with the other TCU that was with the rebuilt trans. I haven't been able to see if it now functions properly, as I obviously bumped something under the dash when disconnecting the Quick Change, as the cruise button lights up, but doesn't engage. I'll take a look at the connections when it isn't 20 below, or when I can get it inside a heated shop.

On the bright side... It looks like I now have a perfectly good trans to put in the '94

[Svx95]

Originally Posted by Chucksta

So.. I found a problem..

To me it sounds like you found a solution! I had suspected the QC as the originator of all problems but Harvey said it wasn't possible for the unit to cause such codes....

Originally Posted by Chucksta

I'll take a look at the connections when it isn't 20 below, or when I can get it inside a heated shop.

I definitely agree with this statement, especially since my QC is soldered it will be a little more time constraining than just removing somesome quick connect clips. Removing it is my next step on the list.

Originally Posted by Chucksta

On the bright side... It looks like I now have a perfectly good trans to put in the '94

That sounds awesome

[Svx95]

Originally Posted by Chucksta

I haven't been able to see if it now functions properly, as I obviously bumped something under the dash when disconnecting the Quick Change, as the cruise button lights up, but doesn't engage.

Maybe, its not under the dash were the problem is. Have you looked under the hood at the vacuum hose that connects to the Cruise Control diaphragm bolted to the firewall? It is easily bumped off the nipple or it could be torn.