The siemans injectors, it seems, do not need to be coded. A local guy with various makes of dealer diagnostic equipment came to program the new injector but there is no facility on this particular system!
While we were finding this out we found a code that my KTS didn't pick up. The code was for injector power supply.
I finally traced the fault to the main loom running over the gearbox - It had rubbed through and the high voltage injector wire was shorting intermittantly. Someone had removed the gearbox and not replaced the clips for the loom.