Tr580 is killing me

[Theyfzman]

Ok kind of a long story but I’ll try to be brief
12 Impreza 2.0 137xxx miles dash board light up with the dreaded lock up selenoid so ordered one off Amazon replaced it and nothing same issue. Car runs fine no shudder nothing !!! So replaced the valve body and again same issue, bit of background I own a repair shop mainly body work but I’m what I consider pretty car knowledgeable talked with a friend that works for Subaru after rolling the above mentioned items out he was leaning towards the actual converter....... so yesterday out it came and go figure drove about 8-10 miles and it literally up on me again with lock up duty selinoid malfunction !!!!! Not a happy camper I might say
So if I clear the code and run live data on my scanner the torque duty percent will fluctuate as it should depending on the amount of gas given but then it just drops to zero and shortly after the code is popped. I’m leaning towards a wire issue maybe. But I’m pretty much at a loss. I don’t want to put a tranny in it if it is an external issue
Any thoughts anyone ??? Greatly appreciated

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[Elbert Bass]

Sounds like your TCM crapped out - assuming wiring is OK. Rodents do like Subaru harnesses. I have only seen 1 TCM cause the lock/up solenoid code since Lineartronics came out in 2010, it is always the solenoid coil changing resistance value.
I am guessing so far you are just parts swapping without any real diagnosis?

You need to measure your solenoid resistance with harness unplugged from the TCM. Measure solenoid resistance from connector to ground with a cold trans. Should measure 10 to 13.5 ohms. When the solenoid goes bad the resistance usually goes higher than 14 ohms or you have an open circuit. Any values out of range you should wiggle test, and visual inspect the harness and connectors to see if the reading changes or there is damage. If all that is good then try a TCM.

Check the wiring for the Impreza to verify the correct connector and pinout.
I know the Outbacks use pin A26 (Red/White wire) connector B54 (14 pin connector) That is the end wire below the Blue/White. At the transmission plug it goes through pin 11 and changes color to White on the transmission side. AGAIN - check Impreza wiring diagram - the above is only confirmed for Outback.
I am assuming since you replaced a valve body you have a way to perform the learning promotion between TCM and transmission? That should be performed anytime you replace a valve body, TCM, or transmission. You should also have a dealer update to the latest version of software for TCM.

[Theyfzman]

I did check the ohm output and it is within spec so ruled that out now ! I didn’t at first due to so many different posts about the solenoids going bad so just figured just go with it and I did do a relearn and it came back positive but within a few miles of driving it pops the malfunction duty solenoid code
What puzzles me is when I drive with the scanner running live data the solenoid is working for a short time I don’t really want to change the trans. If it is an external wiring issue

[Elbert Bass]

Originally Posted by Theyfzman

I did check the ohm output and it is within spec so ruled that out now ! I didn't at first due to so many different posts about the solenoids going bad so just figured just go with it and I did do a relearn and it came back positive but within a few miles of driving it pops the malfunction duty solenoid code
What puzzles me is when I drive with the scanner running live data the solenoid is working for a short time I don't really want to change the trans. If it is an external wiring issue

OK, you have done the basics. And yes, it is almost always the solenoid - I have seen only 1 time it wasn't the solenoid in 9 years and probably 400+ solenoid codes. Which code exactly - is it the high or low circuit code or the function code? The TCM will drive the solenoid until it pops the code, then it quits trying to lock-up, so what you see on duty cycle is normal. These Lineartronics ALL go into full lock-up when over 7 to 9 MPH.

Clear codes, then watch your Engine RPM and Turbine speed values. Over 8 MPH they should be the same value as long as you have Lock-up duty cycle. This will indicate that
A. the TCM is driving the solenoid
B. the solenoid is controlling the lock-up clutch
C. The lock-up clutch is working.

My guess presently without knowing what code and the speed data is your TCM is either has an issue that it cannot "see" the speed data or "measure" the solenoid current draw (how it determines resistance) or the seals on the input shaft are leaking - which is an internal non-serviceable repair. Outside chance you had a bad converter and replaced with the wrong converter, but unlikely.

[Theyfzman]

I will double check which code it is exactly if I remember correctly it didn’t specify exactly. It just stated duty solenoid malfunction And just FYI I own a repair shop I mostly do body work but I’m pretty versed in auto repair overall I will check with the live data and see what those readings are for sure. Thank you so much for your input. That guy that works for Subaru that said pretty much the same thing you said I have the basic’s covered especially now that the converter was replaced. And I got it from a reputable shop and feel confident it is the correct one, it is a remaned one and he stated he was pretty familiar with these pos’s

[Theyfzman]

My gut is telling it’s the TCM I may try to locate a used one. I have a friend at a salvage yard that may let me try it and see. Would it need programmed ? Or just do a relearn ? I have the maxisys autel scanner that works pretty nicely

[Elbert Bass]

Originally Posted by Theyfzman

My gut is telling it’s the TCM I may try to locate a used one. I have a friend at a salvage yard that may let me try it and see. Would it need programmed ? Or just do a relearn ? I have the maxisys autel scanner that works pretty nicely

That was why I mentioned TCM first since you did everything but the trans. Usually a CVT trans fail is a catastrophic failure. Depending on which code you had at first, and if it was the same each time could give us more of an idea.

As long as you can find same year Impreza TCM you should be OK with just a relearn. I no longer work for Subaru so I don't have access to STIS anymore to check the TCM pak numbers.

[Theyfzman]

Ok so the code is P2764 and I took a video of the live data but can’t figure out how to post it but it appears the engine speed and turbine speed are roughly the same turbine lags just a bit. But there close

[Theyfzman]

But the lock up duty percent functioned for about a 1/4 mile it was at 99% then went to zero and remained there til I got back to the shop that seems to be where my problem is ! I’m ready to burn it Not a fan of the CVT

[Theyfzman]

Correction on the code it’s P2764 !!!!

[Theyfzman]

Ok now I feel like a dork ! P2762 and that’s my final answer

[Elbert Bass]

Originally Posted by Theyfzman

Ok so the code is P2764 and I took a video of the live data but can’t figure out how to post it but it appears the engine speed and turbine speed are roughly the same turbine lags just a bit. But there close

Yeah P2762 is not common. Since you verified you have duty cycle, plus turbine and engine speed are within 100 RPM that tells us the solenoid works, the lock-up valve responds and is supplying pressure to the clutch and the converter clutch is operating. The diag tree tells you to then physically verify secondary pressure is between .5 and 1.5 Mpa (72-218 PSI) in Park at idle - the pressure sensor reading will do for that. If that is the case then I would say it's the TCM. Oh yeah - and be sure it has the green or blue CVT fluid - not red ATF.
P2763/P2764 is the most common codes which is the indication the solenoid fail due to change in resistance.

[Elbert Bass]

Originally Posted by Theyfzman

But the lock up duty percent functioned for about a 1/4 mile it was at 99% then went to zero and remained there til I got back to the shop that seems to be where my problem is ! I’m ready to burn it Not a fan of the CVT

If it went to zero AFTER the code set/warning lights came on that is normal. Once the code sets it goes to limp mode which is without lock-up function.

[Theyfzman]

I can’t thank you enough sir !!!!
The lock up percent drops to zero then you have to drive it for sometimes a mile sometimes 5-6 miles then it pops the lights and the code
I’m going to try a tcm this week and see what happens I’ll let you know
Thank you again

[Theyfzman]

Well put the used tcm in this morning and getting the same issue lock up duty solenoid malfunction
On the live scan it fluctuates the duty ratio percentage for about a 1/2 mile or so and then drops to zero
So FRUSTRATED !

[Elbert Bass]

Originally Posted by Theyfzman

Well put the used tcm in this morning and getting the same issue lock up duty solenoid malfunction
On the live scan it fluctuates the duty ratio percentage for about a 1/2 mile or so and then drops to zero
So FRUSTRATED !

Ok. What range does that duty cycle fluctuate within before the fault? It can vary depending on the driving conditions and load. I have never seen one go below 65% - even coasting.
I may ask some questions again for clarification of details.
When you swapped the valve body did you make sure the two O-rings were in place under the valve body?
Get the ground wire under one of the bolts on the top cover?
Did you ever verify that secondary pressure reading?
When the duty cycle was above 65% was the difference between the engine and turbine speed 100 RPM or less?
Have you checked the harness down the left side of transmission (behind the black covering) for pinches or cuts? especially at the turbine speed sensor and pressure sensor? No rodent damage to that harness?

I am stuck here - Without seeing a drive cycle recording of TCM data I am at a disadvantage.

[Theyfzman]

I will check out all of those items and report back

[Theyfzman]

Sent you a private message elbert

[Theyfzman]

Email didn't work sir