i had the computer replaced and it still wont start because there is a code that says the key cannot be read What could this be
You could have a bad key or something related to reading the key has a problem. Isn't a 2016 Lexus still under factory warranty?
The engine's computer is encoded to the transponder key & ignition sensor and theft module ECU, if you replaced the engine's computer it will need to be re-encoded to those other components, most likely this will have to be done at the dealership.
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