And then about the blinky "security" LED. Why bother? Well, I didn't get all keys with LC I purchased and need to visit a Toyota dealer soon to get spare keys made and programmed. I read about the blinking patterns providing feedback about the immobilizer function of the keys so just to make it easier for me and any service tech that may not be too thrilled to work on a vehicle with a non-stock dash I took a shot at trying to find out how to get this LED back. That appeared to be easy after having already gone through the trouble of deciphering the connection between AC amplifier PCB, vehicle wire harness and central diff lock PCB. The security LED is powered by a line located on pin 24 of the connector from the Android radio to the AC amplifier. Add a wire to this connector to drive a 470 or 560 ohm resistor plus LED, connect the other side of the LED to ground and you get the security LED function back.
Add the additional wire on the 24 pin AC amplifier connection (the yellow wire was added):
View attachment 2728245
The contact is a JST contact, these are the same as used in "grove" sensor connectors, search for a "grove sensor cable" to source and reuse a pre-assembled contact+wire.
Connected a small 3 mm LED and placed it just below and inline with the MIC and reset functions on the left side of the Android radio display:
View attachment 2728251