This Passat is booked in for Monday but as it arrived early I took a look today. I didn’t have my scope to hand so did a few checks with a meter.
It is running off cyl 3. There is a code for cyl 3 inj output stage open. The 12 v supply to the injector is ok. I have 12v on the ground side koeo. I have 12v at the ECU pin (58). I swapped number 2 and 3 inj plugs and the fault code was still for number 3. This already had a used ECU fitted and the old one came with the car. I swapped it, still the same. I had a similar ECU on the shelf, swapped that in, still the code for number 3 inj. Thinking I may have a partial short in the wiring I snipped the wiring and ran a new temporary one in, no change.