Range L322 TD6 starting problem, serious...

I got one L322 (or MKIII) RR to my shop. It didn't start. Owner had bought it a few weeks ago from germany and recently driven it home to Finland. Suddenly, one morning it didn't fire up. It cranks the engine well but not fire up. So I basically tought that it was fuel filter frozen up or something very simple.

Now it has been lying around our shop for a week or so and customer is getting more angry all the time and I think he blaims me for the car to broke up... Now I'm really in deep shait with this. I've contacted finnish official Land Rover service, they don't know a thing to cause this.

Symptoms:
Car won't fire up, cranks well though.
With all the testers it wont let me through to read DTC:s from ECM, EAT and ABS ecus... Completely dead.
Gear shift lever signal doesn't come up to instrument pack, so no P, N, R or D and so on on the screen... (basically, it doesn't know which gear is on...)

What have we done:
We are able to read pending DTCs from all the modules except these three as mentioned on symptoms. BeCM and instrument pack (and several other modules) says that the fault is in the CAN. Erasing won't help.
For now we have checked diagnostic socket wiring, checked that there is no water in any electronic system. (Found though marks of water to short circuit ABS module socket pins 2 and 13 (and maybe also nr. 3)... But it can't burn three whole modules can it?!)
I've checked all the fuses, no one is broken.
I've cleaned all the ground points in engine bay. Light washer wipers started working when this was done... Something positive.
Immobilizer says "mobilized", but I noticed as I said before that every box doesn't get the signal from auto gear switch lever.

What should we do?
Could it have burnt whole three boxes? Or just the can controller gateway thingie (in the middle of the fascia panel?)?
Is there any more grounding spots than the five in the engine compartment? Has to be but does it affect these boxes?

It's getting a bit late when working on this message. I've propably forgotten something that I've done or checked... Just ask everything that pops up to mind... I'm totally helpless! I did search for help from this forum, but nor did I found anything. English isn't my first language, I'm from finland but hopefully I write better than I speak english... This thing really pisses me off and I just want to get rid of this job... I'm such a stubborn guy not to give up early enough. Now banging head to wall... :think: