Ok so some success today!
Ive blown a few modules now and bought a few more spare off Ebay.de.
Today I decided to connect 3 short wires to a spare rear sensor but near to the module i.e. not connecting the module up to the rear sensor and cabling running to the back of the car. I dont have the front sensor installed but do have the sensor so I connected this up under the dash next to the module too.
Voila success, the front and rear sensors were showing in the measured values. I cleared the fault codes, got the sensors 'learned' in the learning function and all ok.
I therefore thought that the problem is in the wiring to the rear sensor and it is shorting somewhere hence I kept getting the fault code short to ground for the rear sensor. To prove this theory and I didnt mind blowing another module as this was the older type of module and I had two more later modules spare I decided to reconnect the wires back up leading to the rear sensor. The module blew.
I conclude this is the problem and I need to take out the old cable and replace.
I plan to do this next weekend possibly, the car will then fully comply with Mot regs etc, self level up hills and no swapping of headlights to halogens... so from halogens I have changed to xenons, installed the headlight washers and finally self levelling.
You can see in the measured values there are now readings for the front and rear sensor (%age values).
The first picture you access the Can gateway module and tick '55 Xenon range' this then allows information to be communicated to the module via the brown/orange black/orange can wires connected up to the module.
The 2nd picture you can see the module isnt working and theres no readings from the sensors.
3rd picture I have cleared the fault codes after replacing the module and all ok, no errors.
4th picture sensors wokring, measured values
5th picture, sensors not working no measured values.