Hi Ray,
The BCM will be in the rectangular black housing on the nearside of the engine bay under the scuttle panel, coming forwards towards the fusebox. A long blade torx driver will save you removing the trim by the wiper arms. The BCM is the black module next to the relay plate inside there (roughly VHS tape size).

I've had some Corsa C's with bad CAN wiring but the last was a water damaged BCM giving all of the codes you have. I had the same symptoms of running for a few seconds but that would depend on whether you unlocked the car and immediately cranked it or if it was unlocked and left alone for a while before cranking. I think it would only crank and never fire if left for a few minutes after unlocking but it may have been the other way round.

I would go through the multiplugs as you have said and definitely the engine ecu connectors and ABS controller multiplug if fitted. Also the Easytronic module if it has one but if you don't find anything there it would be worth a look inside that housing to check the BCM. I think you would have different codes if it was just a bad ins cluster. The CAN wiring going into that BCM housing can be damaged where it comes up past the fuse box in the engine bay as well.

I take it you have TIS, as you mentioned using Tech 2, so it's easy enough to check the CAN wiring between each module from the wiring diagrams.


Liam