Hi, I wanted to inform you about this procedure to be carried out after replacing the engine control unit (in this case used), since this car was found to be faulty and to solve the problem of immobiliser coding, there is no scoding of the control unit, but a "reset" or "synchronisation" between the engine ecu and the immobox is necessary, it is valid on many toyota models, I have carried it out successfully on this aygo 1.0 engine code 1kr-fe, without the need to use the official toyota tool, it could also be valid on c1 and 107.

IMMOBOX - ENGINE ECU SYNCHRONISATION PROCEDURE:

NOTE: Due to the duration of the procedure, the use of a charge maintainer is recommended.

Step 1: Switch on the instrument panel (do not start engine) using a functioning master key.

Step 2:  Make a bridge between pin 4 (CG) and pin 13 (TC) of the EOBD diagnostic connector.

The ABS, STOP, BELT and ELECTRIC STEERING INDICATOR lights will start flashing

Step 3: Wait 30 minutes
Step 4: Switch off the instrument panel and remove the bridge from the eobd socket.
Step 5: Switch on the ignition, start the engine.

NOTE: this procedure is useful in case of engine ECU replacement (new or used), it is a RESET of the coding stored in the engine ECU, it does not solve key recognition or immobox problems.

I hope it can be useful.

Greetings.