[jlach9]

I had a 2012 tundra serviced at 50K miles in 2016 and did the whole dealer recommended ordeal, including a transmission fluid flush.

On the ride home after that, the check engine light came on and it threw a solenoid code. I was able to clear it and it would stay off for a while (months). Truck is only at 90k now, but has been having a weird issue transmission wise and I can't get the codes to disappear. It feels like its skipping/twerking (sort of like when the traction control kicks in on a wet road) from gear one to two. It doesn't do it every time. Sometimes it doesn't do it at all. It's an automatic and only has issues when going from a stop to moving, intermittently.

I took it to the stealership when this first started and they told me I needed a new tranasmission. And a new rear windshield wiper, lol. They said there was a ton of metal in the fluid. They flat out refused to show me the magnets or metal. I took it to a real transmission place after that. They dropped it and said it was an electrical issue as the transmission was perfect. They didn't have time to check every solenoid. I took it to another transmission place. They also said the transmission was in perfect shape and said they tested all of the solenoids but couldn't find the issue. They suggested it's possibly the ECM.

The codes it's throwing are
P2759- Torque converter clutch pressure control solenoid circuit control circuit electrical
P0748- Pressure contol solenoid A Electrical
P0980- Shift solenoid C Control Circuit high

I was wondering if anyone had ideas for anything I could try before dropping a few hundred on the ECM. I also have a 2016 tundra that I can steal parts from to test (from my main truck, this one with issues is my work truck), although I don't want to take the transmission apart myself.

 

[Blenton]

Have you checked the transmission fluid level? Do a drain and refill; it involves about 4 quarts of WS fluid and a strict but not complicated fluid level check procedure. Use a clean, new catch can and inspect the fluid yourself. If it glimmers then the trans is in trouble. Also inspect wiring around the transmission for damage. That could easily be the culprit as well; often intermittentl solenoid issues are wiring related.

Honestly, this is something that should have been addressed immediately after the fluid flush six years ago. Hindsight, yes. And I understand needing to use a vehicle but there’s a start. I would not swap parts between the trucks; keep the 16 running strong.

 

[stomachbuzz]

I believe I have a similar transmission issue.
It has not thrown any codes though.
I got the truck at 80k miles. Now has 120k.
It has done a hard shift from 1st to 2nd gear (pretty much always when coming from a stop) for the entire time I've owned it. I've flushed the transmission 2 or 3 times. Replaced all the fluid. Dropped the pan, replaced filter, inspected the underside.
I've also plugged in with Techstream and not found anything.
It's done it the entire 40k miles I've owned it. Hasn't gotten any worse. It's one of those things that bugs me, but 95% of people wouldn't notice it even if you pointed it out.
My truck is a 2008, so maybe it's too old to have firmware to trigger OBD codes based on those transmission issues.
It could be a firmware thing, or a 'learning procedure'. Not sure. For me, it's just one of those things that I shrug and say "whatever. I tried. Not much I can do"

 

[Blenton]

That harsh 1-2 shift is often times not the transmission, but the driveline and rear axle. The rear springs can soften and wrap up in first gear. When it shifts, the unwind then bump as you hit second. Basically axle wrap.

 

[imcougar]

I believe I have a similar transmission issue.
It has not thrown any codes though.
I got the truck at 80k miles. Now has 120k.
It has done a hard shift from 1st to 2nd gear (pretty much always when coming from a stop) for the entire time I've owned it. I've flushed the transmission 2 or 3 times. Replaced all the fluid. Dropped the pan, replaced filter, inspected the underside.
I've also plugged in with Techstream and not found anything.
It's done it the entire 40k miles I've owned it. Hasn't gotten any worse. It's one of those things that bugs me, but 95% of people wouldn't notice it even if you pointed it out.
My truck is a 2008, so maybe it's too old to have firmware to trigger OBD codes based on those transmission issues.
It could be a firmware thing, or a 'learning procedure'. Not sure. For me, it's just one of those things that I shrug and say "whatever. I tried. Not much I can do"

I have same issue described here. It’s almost like the truck is stuck in between 1st and 2nd gear and won’t go either up or down. This happens from a stop as well and it is even more noticeable when the weather is cold. I usually have to let go the gas and then hit the gas again slightly harder to get it going. After driving for a little while, issue would go away for the entire drive until the next drive in the cold again. I have let the truck warm up and Tran temp goes up but it still does it and what’s annoying too is It doesn’t do it every single time in the cold.

 

[MB10Tundra]

I have had this issue as well. I ended up flushing the trans and it disappeared for a while. It is starting to rear its ugly head again, but no codes. This is on a 2010 DC 4wd 4.6L. I’m at a loss as to what is causing it and why. I have noticed that if I switch to the manual shifting it doesn’t rear its ugly head. Have you tried doing that? Not sure if that year truck was equipped with the manual shift or not. It all makes me think that something near the torque converter is messing up with the fluid levels and sending of fluid.

 

[Sefiro]

I have worked on many a transmission, but not Tundra. The code descriptions suggest an electrical problem.

The first 2 suggest incorrect signal coming back to the ecu. The 3rd code suggests a short (likely on the wire harness internal to the tranny but possibly in the external harness.

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[H2O MAN]

Never perform a fluid flush, always drain and fill.

 

[Sefiro]

Never perform a fluid flush, always drain and fill.

Ditto , do not let a shop use a power flush machine unless you do a flush every 30-40k.

Bbuutt
You can let the tranny flush itself.

• find the pipe to cooler
• disconnect and place a vinyl tube on it and run to a 5G bucket
• start and run truck for a few minutes monitoring the bucket 1-1.5 gallons and stop truck
• measure amount removed and add rhat amount back in.
• repeat until you see clear fluid coming thru the hose.
• top off and put it back together.

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