The blue light is not flashing rapidly during step 4 of the programming sequence on a 2015 Toyota Highlander

Question

The only reason I can think of is that the can-bus wires may be wrong.  There is no black wire in the obdII connector.  The wires on the schematic call for a "white" CAN high and a "black" CAN low wire.  There is not a "black" wire in the entire OBDII connector.  There is a "violet" wire in the position where the "black" wire should be.  In addition, the "white" wire and the "violet" wire are twisted together as they leave the OBDII connector.

Answer 1

If they are twisted together this must be your CAN Network. Verify the pinout according to guide.

Your option A3 (Key Bypass) is off, it needs to be on.