2009 V6 auto - first real problem - trans

Finally coming up on 100k miles and I have a trans issue. Trans is actually fine 90% of the time and shifts normally and solidly. But coming out of low speed turns like at intersections sometimes when I give it gas the engine revs like it is in neutral and then bang, it shifts to second chirping the tires if I leave my foot in it. This is not "slipping", it seems like it is getting confused releasing one gear and not engaging the next. I am thinking I might have a balky solenoid or somesuch. I know it is "due" for a fluid change at 100k miles but I don't believe it needs that. Anyone encounter similar?

 

#1 fluid change if never done
#2 if that don't work let a professional Trans. repairman look at it
#3 still may have a warranty on the Drivetrain?

 

Any input @gearcruncher ? Failing solenoid?

 

I haven't found a schematic yet but there have to be at least a couple of shift solenoids and a TCC solenoid. If I can find their locations I can pull them and put a meter on them and give them an op test. But if the problem is intermittent that might not be definitive.

 

Find out what is wrong BEFORE you start fixing stuff that might not be broke. It sounds electrical to me. I've not had any issues with my Tacoma, but our 2009 Honda's transmission was throwing codes and shifting funny like that. I was quoted $2K to rebuild the transmission. Thirty minutes after dropping it off at the shop I got a call telling me it was ready.

The mechanic did some poking around before pulling the transmission and found some electrical wires that mice had chewed through the insulation causing a short against the housing. They put some shrink wrap over the exposed wires and charged me $50.

 

You can try these?

https://atracom.blob.core.windows.net/webinars/import/toyotaa750_a761_introduction.pdf

https://www.sonnax.com/tech_resources/375-toyota-lexus-a750e-f-solenoid-identification

 

That info helps. Super useful post! it sure sounds like it might be the S2 solenoid that controls the 1-2 and 3-4 shifts. I see this behavior mostly on 1-2 but also on the 3-4. Now I need to go back those links or elsewhere to see if I can find the S2 location. If it is externally accessible like on many vehicles that will be a quick thing to pull and test. Also could be the clutch apply solenoid hanging up and then switching. They are all in the same place so if/when I open it I'll test them all.

Edit: oh I see from the second link that these are in the valve body under the pan on our Tacomas. A bit more work, then. Hmmm... Darn. On many cars they can be pulled from outside the case with one bolt.

 

Something has to plug into those externally from the trans. Try to find a pinout and test it at the ECU/ BCM. Or get a cracked version of techstream for data logging or special functions / bi-directional control. Maybe @caribe makaira can point u in the right direction on the pin location.

 

That might work to ohm them out, but not to observe plunger stickiness. But it would be a good first step if I can find the pinouts.

 

For sure just measuring resistance. Throw a bottle of brake clean in your trans, it'll get rid of the stickiness REAL quick

 

Brake kleen....

 

LOL... or the all purpose, fixes-everything Sea Foam, right?? ;-)

 

Exactly

 

The symptom you are explaining sounds like low on trans fluid . For what its worth I would check that first .
Not sure about sea foam for transmissions ? Lubeguard is good
Trans fluid should be changed every 30k under normal driving operation
Are you running a scanner of any sorts ? got any codes ?
Next thing that comes to mind is the SLT solenoid
http://bluegrasstoday.com/wp-content/uploads/2012/07/a750e_shudder.pdf

https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

No codes, no leaks. If only we had a dipstick. But any fluid loss would have to be magical with these sealed trannies in the absence of a leak. And it doesn't do the usual things with low fluid like not going into D or R immediately. That is usually the first sign of that.

I was kidding about the Sea Foam. I prefer my transmission fluid straight, thank you very much. You'd be a fool to put that stuff in there.

 

Transmissions are not sealed as stated by the Tacoma dealer hehehehe
Your trans fluid can drain into the transfer case , can drain out the overheat vent , and in a worst case scenario , it can drain into your cooling system causing the dreaded strawberry milkshake .
When turning corners , all your fluid moves to one side of the pan causing the transmission pump to starve for fluid . Once the transmission gets very low , you will notice delays to first gear and reverse

 

Interesting... I definitely don't have the milkshake and none in the TC at the last oil change... and I have never towed anything to overheat it. But I guess I could pull the plug and have a look. But I need to go look at that procedure. I remember looking at the fill procedure years ago and it involved getting the tranny to a specific temp and filling to the fill plug IIRC. I have no idea what temp, however, and no way to measure it regardless. I curse Toyota for omitting a simple dipstick.

 

Nudging 200k, did a flush and fill early at 70K at the stealership. Now she asks for a 1/4 quart about every 30K. Funny how being a smidge low hurts so much..

 

The steps to get into Temp Check Mode are here

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/