The 2zr-fe engine swap guide

[CrankyOldMan]

The 08-09 xD did not have an immobilizer. The 09+ Yaris does. From what I can tell, the immobilizer has dedicated signal lines to the ECU. If the signals aren't there, the car won't turn over. My thought is that if the ECU doesn't have the inputs from the immobilizer in the first place, it doesn't matter that the key transponder and immobilizer are still in the vehicle. As far as I can see, there's no other connection from the immobilizer to the starter switch or relays.

Take it with a grain of salt, I haven't actually done the swap.

Edit: Here's the wiring diagram for the Yaris immobilizer. The only communications line that doesn't go directly to the ECU is pin 9, which is wired to the OBD II/DataLinkConnector (pin 7 - SIL). As far as I know, that's only used for external diagnostics. I would add a picture of the xD, but there's nothing to show for unused connections on the diagrams.