These introduced Drive-by-Wire (ETCS-i) . The pinouts changed to accommodate the electronic throttle motor and pedal position sensor.

Most 2UZ-FE ECUs from 2000 onwards are "locked" to a specific transponder key. If you don't have the original key and the amplifier ring, the engine will start for 2 seconds and die. You may need an Immobilizer Bypass or a "virginized" ECU.

Because the 2UZ-FE was produced from 1998 until the early 2010s, the wiring evolved significantly—moving from early non-VVTi throttle cables to complex VVTi systems with secondary air injection. Understanding the 2UZ-FE ECU Variations