X5 3.0d won't start

[F1Pilot]

Ok, so not having much fun here! Car was running great, took off down the road and was off the accelerator.
When I went to accelerate again, nothing.
No lights, no warnings, no coughing, nothing.

The car would crank but would not start.

Towed car home, so far I found that the ECU is not turning on the fuel pump relay and therefore not turning on the pumps. I jumped the pins at the relay and both pumps turn on and sound normal. I have also tested the relay and it works fine by itself. I tried to start with the relay jumped (pumps on), but no go, so I'm guessing the ECU is not seeing something and not allowing the engine to start.

It is at a local garage. They have a very good scan tool and read 10 fuel related codes, that they cannot erase. These codes also do not know pinpoint the problem for them.

So, what would cause the ECU to not turn on the fuel pump relay/start engine?
ECU failure?
Ignition switch?
Faulty key/immobiliser?

Battery was charged and tested. All good.
Any help greatly appreciated, of course this had to happen at Xmas!