Willing to put money that this is either a transmission itself or its controller issue (TCU).

 

You need to take it to a Lexus dealership and have them diagnose the problem. Could be anything from corrupted controller firmware, which could be cheap or expensive to fix, to carbon build-up (not all symptoms are identical), to transmission problems, etc. No-one can diagnose it from this forum - need to be there with the car.

 

Definitely needs a trip to the dealer...I wouldn't trust independent shops for issues like this.

 

Agreed. Not an engine issue. Either transmission or transmission control issue. As it works fine when it's cold I would steer to the mechanical side / valve control. I would let Lexus fault find even if you don't get it repaired there.

This might sound strange but next time out. Stick it in snow mode and see if you have the same issue. Snow mode operated the valves completely different to normal mode.

 

ok guys

two codes come up

b2799 c1203

another thing is when the car is on .. the voltage is 13.3 V

but when i put it from R to D the Voltage comes down to 13.1 V and it starts shaking.