Only 1 bad sensor and the entire system won’t initialize. If it flashes when you start the car a sensor is bad. Immediate solid means you have a low tire or you pressed the button too many times and shut the system down.

 

2017 rx 450h, I had to replace tires in October and right after I left a tire shop, tpms stopped working and the light eventually came on. The scan showed 3 sensors were bad. I went back to my shop, they reset it all and said it should work. It didn’t. I decided to buy 4 new Lexus sensors. They replaced one at first, free of charge, and said all works. It didn’t. It sort of did, when I drove out of a heated garage but not when a car was in the -20 C cold the whole day outside. Few days later it stopped working again and the light came on. I had to schedule another appointment and they replaced other 3. They were very kind and replaced it for free. Now it all works.

the lesson are:
1. 9-10 years and the battery gets weak, may work when warm only and fail when cold
2. replace all 4 at once.
3. If one does not work, then nothing works, Lexus tpms system is useless.

 

I just had all 4 sensors replaced for $288 at Tire Discounters. 2017 IS300, had the exact same issue where tire light flashed on startup, no pressure reading on any of the tires. It is fixed and working fine.