How and what exactly do I check?

AUDI A3 TDI 8P

http://wiki.ross-tech.com/index.php/00470

I get the fault code,but everything works ok on the car,it says ''woking in single mode'?
check measuring blocks and do what exactly,and what is the comfort module for?

got this when central convenience unit got some moisture from small amounts of water in the boot,unit itself didnt get wet,and i couldnt get the connectors off (must have corroded on ) so i sprayed wd 40 in the plug/connectors......but like i say everything works 100%
'JUST HATE 1 FAULT CODE IVE GOT' (mentioned above)

Thanks will look into this when it stops rain/snow

NHN said:

Check both canbus wires going into the units on that bracket in the corner, it sounds like one wire is shorting out so you have as it says single wire operation of canbus as they have 2 wires, high & low, one is not working, so remove the pins from connector plug & check for corrosion, also check the pins on the module itself, scratch them a little

Click to expand...

just done it ! cleaned it up there was green (corrosion) around 3 points on the brown plug..wd40'd used a needle to scrape in the plugs and scraped the pins with a thin screwdriver....il check with vag over the weekend if its the same then il put it down to the convenience unit.but hey its no big deal......at least all is working!