AT Oil Temp light is NOT on.

I have 2006 Sequoia 2wd with an A750E transmission.
To make a long story short - I had to do drain/fill at 200+k mileage.
Now I'm getting problems after a hard stop in Drive (I've checked that switching to Neutral during the hard stop prevents any issues) - on a stop, I get a hard hit, and gears won't switch as expected (sometimes stuck on 1st or 2nd gear, rarely goes up to 5st gear etc. Usually without error codes, though from time to time I'm getting code P2714.
95% that the oil level is not correct, 5% that it's the solenoid.
I know how to set the correct fluid level without the techstream (though recommendations how to get it on Windows 11 without a virtual box would be appreciated), but the issue is that AT Oil Temp is not working at all.
When I just put the key in and turn the ignition on - the light stays off.
When I try to enter Transmission Check Mode - it won't light on.

Any suggestions where to look for it and what to do to make the light work and set correct oil level?
Also is it safe to add Lucas Oil Transmission Fix after all?

 

• When not using the intelligent tester (using indicator light):

1. 
   1. Using SST, connect terminals 13 (TC) and 4 (CG) of the DLC3.
      
      SST
      
      09843-18040
      
      
   2. Start the engine.
      
      NOTE
      
      Check that electrical systems such as the air conditioning system, audio system and lighting system are off.
      
      NOTE
      
      HINT:
      
      Indicator lights of the meter blink to output DTCs when terminals TC and CG are connected.
      
2. Slowly move the shift lever from P to L, and then return the shift lever to P.
   
   NOTE
   
   HINT:
   
   Slowly move the shift lever to circulate the fluid through each part of the transmission.
   
   
3. Move the shift lever to D, and quickly move it back and forth between N and D (once within 1.5 seconds) for at least 6 seconds. This will active the fluid temperature detection mode.
   
   
   Standard condition
   
   A/T OIL TEMP warning light remains illuminated for 2 seconds and then turns off.
4. 
   
5. When not using the intelligent tester:
   
   1. Return the shift lever to P and disconnect terminals 13 (TC) and 4 (CG).
      
6. Allow the engine to idle until the fluid temperature reaches 36 to 46°C (97 to 115°F).
   
   
7. The A/T OIL TEMP warning light will come on again when the fluid temperature reaches 36°C (97°F) and will blink when it exceeds 46°C (115°F).
   
   
   NOTE
   
   Perform the fluid level inspection while the indicator light is on.
   

6. CHECK FLUID LEVEL


NOTE

1. The fluid temperature must be between 36°C (97°F) and 46°C (115°F) to check the fluid level.
   
   
2. Do not insert the fill nozzle into the refill hole more than 30 mm (1.2 in.) to avoid contact with the moving parts.
   

1. Remove the overflow plug with the engine idling.
   
   
2. Check that the fluid comes out of the overflow tube.
   
   
3. Wait until the overflow slows to a trickle.
   
   If fluid does not come out, perform the following.
   
   1. Install the overflow plug.
      
      
   2. Stop the engine.
      
      
   3. Remove the refill plug.
      
      
   4. Add 0.4 liters (0.21 US qts, 0.18 lmp. qts) of fluid.
      
      
   5. Allow the engine to idle.
      
      
   6. Remove the overflow plug.
      
      
   7. Wait until fluid begins to trickle out from the overflow tube.
      

 

That’s the problem. My A/T OIL TEMP light doesn’t work. It won’t come on…

 

Strange.....

Does it come on - Key ON, To run position , Engine off?

 

Alot of scan tools except the cheapo generic ones can read trans temp, you don't necessarily need Techstream.
If you have a temp gun you can get close enough as well.

 

Not working, that’s the problem. also I’ve checked the dashboard, the led is there and not closed, so it should work.

 

well, there is a problem.
I can grab diagrams for you if you want to see why/where it isn't working.
I can't imagine the LED is burnt out? But possible I supose?

 

I have Vgate vLinker FS USB left from my Ford Explorer. I wonder if it will work with Toyota and what software should be used with it then?

 

I doubt. Most probably disabled/cut somewhere. This car has some history from previous owners. Check light and a few traction control lights were covered with black tape under the dashboard to look always off. TPMS light was disabled by grounding one cable. So I think they could do something with this one as well.

 

Not familiar with that tool but if it can read transmission data it should work.