Key fob
1. If you cover the remote face with one hand so it's in the dark, and press any of the buttons with the other hand, can you see the red light at the top right next to the Lock button? Is it nice and bright?
2. If you approach the driver's door with the key on your person, and touch the inside of the handle, will the door(s) unlock?
3. What message does it say when you try to start the car and it doesn't? And ultimately how do you end up starting it?
Does the second key work correctly? (Is the second key inside the car?)
Does your key ring have another keyless style fob held nearby?
I know you said you saw the red light, but it has to be bright. I realize bright is subjective since I can't see it.
If you see the light, then at least the battery isn't completely dead.
If it doesn't find the key in the car when starting, then hold the Lexus emblem side of the key up to the Start button and at the same time press the Start button...it should start immediately.
The Start button will actually trigger the transponder in the key so that it can be detected.
The car sees the keys using oscillators...there is one in the drivers door that sees the key when it's outside (as you approach the car). Once you're in the car then it switches to the interior oscillator to see the key inside the car (there is one for the trunk too)
So if the Smart Entry and push Start both aren't working, then most likely its the key, as that is common to both systems.
I know you said you replaced the batteries with reputable brands, but maybe they're just duds. Maybe try another battery.
Also double check there are no other Smart keys of any kind inside the vehicle.
it will not unlock. Pressing the outside unlock button will work but the door sensor will not.









