Would the RFI chip in they keyfob of a 2019 car be truly inert ? I understand it does not need a battery as it derives its power from the incoming RF signal, but would it perhaps have an EEPROM to store the particular code for that car and some digital processing circuits. So there would be active components (in the transistor sense) that could fail, rendering the key inoperative. Though it does seem that super sensitivity to key proximity is the main fault mechanism for the immobiliser not being unlocked.
Does anyone know exactly which chip is used in the keyfob ? Just curious (as ever....)
Not inert but maybe passive Dave in the sense it uses none of its own energy. The RF energy comes from the car. Probably simpler than you imagine although likely a programmable chip.
FWIW just found another source which suggest transceiver frequency is 433.92 MHz in Europe so bottom end of UHF band.
