No high gears!

Hey guys, I bought a 2007 Tundra 2wd with a 5.7 about 8 months ago or so. Been great up until a few weeks ago. Did general maintenance, new tires, pads and rotors, serpentine belt, etc... felt good about everything.

Truck has like 230k btw.

Cruising to work about 60mph and suddenly my trucks downshifts and my rpms are way up and my dash lights up with warnings. VSC OFF light, traction control off light and check engine light. What the heck. I turned around and drove slowly home.
I'm getting 3 codes that I've read.

P0973 shift solenoid A control circuit low
P0751 shift solenoid A performance/stuck off
P2714 pressure control solenoid D performance stuck off

So what did I do next? I checked fluid level on that check plug. Seems good.

Next I drained the fluid, broke 8 of the 12 pan bolts... nice, and pulled out all the solenoids in there, one at a time. Put power to them, and they all clicked. Darn was hoping to find one bad and be obviously at fault. So I'm like what the heck... maybe they are clicking and moving but still at fault, so I checked with my multimeter. No clue what ohms they should read but the smaller shift solenoids read all the same, and the bigger pressure control solenoids read the same as well.

So what should I do next??

 

Sounds very similar to when my wife's transmission in her 2011 Sequoia went out. Hers went into limp mode the first time. I shut off the engine and restarted, it ran good for about 1 week. I should have taken to a shop immediately. Was on the highway when it finally started really slipping and did almost exactly like you described. Took to a friend/mechanic and he said lots of metal shaving in transmission. He found us a used one from a totaled Tundra (rear ended) with only 7k miles. Ours went out at only 130k miles, bought it with 122k miles. The previous owner must have ran it really hard. Ours is a 2wd with 4.6 Liter. Best of luck getting yours back on the road.

 

I had a D4 solenoid go out with identical symptoms but different but similar code. It cycled fine and measured at the edge of acceptable resistance. Replaced, cleared codes, and its been great for 10K.

Fwiw, I spent $ on a Toyota solenoid and it was the same OEM brand as the cheap ones on Amazon.

 

Did you check for bad wiring upstream of the actual shift solenoids? Critter get to them or a pinched/burnt wire?

 

Truck entered 'limp' mode w/the error codes... which is why the dash lights all lit up.

In addition to the shift solenoids, you can also end up w/bad pins (connectors) within the harnesses and such...

Definitely not fun to try and chase those types of issues. Like Blenton said, you'll want to check not only in the pan, but connections running to the transmission, and up to the main harness. Terminals on the exterior of the transmission are susceptible to corrosion depending on what part of the country the vehicle spent most of its time in.

 

I'll check out what the plug looks like in a few days... someone told me maybe it's just bad trans fluid. What came out is pretty nasty. Had some 'silver sludge' on the bottom of the pan by all the magnets but original fluid 230+k miles I figured that would be normal.

I guess I should check wire continuity from plug to different solenoids.
Sold my Chevy for this thing, didn't expect trans problems so quick! What I get for buying something pretty high mileage lol