for those that read this post in the future, BAS in UK offer a service to remove the immobiliser feature in the 2.4 Puma ecu. Not sure, but think that it cannot be done with the 2.2 Puma.

Having poured over the schematics and info i could find on the immobiliser feature at length in preparation for my engine conversion, you need to reprogam the 10AS to remove the immobiliser feature (easy with a Nanocom) and program the 2.4 ECU too. If you do not do both, the ECU is still looking for the serial signal from the 10AS. The 10AS sends a serial signal to the ECU, if the numbers match in the ECU, 2 things happen, the ECU provides a ground for the starter relay coil (the +ve for the coil comes from the ignition barrel) and it allows the ECU to control fuelling.

The TD5 works slightly differently. The 10AS sends the serial signal to the ECU and the ECU manages fuelling. However like the 200tdi and 300tdi, the 10AS provides the ground for the starter relay coil. I've not tested it, but my theory for the 200/300tdi, if you have immobiliser issues, ground pin 85 on the starter relay to bypass the immobiliser.