I just brought home a 02 B5.5 Wagon last night. AVB TDI engine, manual trans. Drives lovely.
Retired my 20 year-old B4 Wagon for it 
There were a few issues with the car when I went to view it last week:
central locking key-fob only locks/unlocks drivers door and boot.
central locking from the door switch only locks/unlocks drivers door
Passenger window is unresponsive from both switches, turning and holding key in lock etc
rear right window rolls up and down in a start-stop manner
fuel flap lock is stuck in the open position.
fuel flap switch in the door causes no response
Boot-popper switch in the door does nothing.
Left mirror adjustment doesn't work from the switch.
The little red illumination on the interior switches flicks off and back on every 5 minutes or so.
The outside temperature readout is always "--.- C", on both the clima display and the multifunction display on the dash.
Clima makes a quiet ticking noise.
rear wiper is dead
I'd done a bit of reading before buying the car and was confident that the CCM was causing most of the trouble (wet left-side carpets). I was able to leverage the "electronic gremlins" to bargain a better price happy in the knowledge I'd be able to sort the problems myself with the help of a few good how-tos here on UKPassats.
So this morning I removed the battery to unblock the bungs but found that the area was nice, clean and dry, both bungs have already been removed completely. After some further reading here tonight I reckon the pollen filter housing is the source of the wet carpet problems. I'll reseal that myself next chance I get.
I lifted the wet left carpet and pulled out the black CCM box, opened it up and found the CCM itself was nice and dry. Opened its case to see it was spot-on, no damp, no corrosion etc. However, there were about a half dozen wires from the CCM into the loom that had been bared, twisted together and taped up in the past. As expected, they were horrible, corroded, wet, green etc. I trimmed each of them back and reconnected them using crimped-on spade connectors. I know it's not as neat as soldering and heat shrink but it's what I had to hand and I'm a firm believer in doing your best with what you have to hand. Checked each joint for continuity across the joint before retesting the problems.
All the problems persist!!My work did nothing but make the joints in the loom a bit neater.
Has anyone got any wisdom to share with me, a total newbie in the world of B5.5 Passats?
thanks
Oh, I suspect the car has been clocked, it's almost 13 years old, has had 10 previous owners and has a caravan socket on the back but shows only 200,000 kms (120,000 miles or so). Is there any way of knowing through VCDS or anything? I'm not that bothered, I bought it on condition moreso than history but I'd just like to know. I'm going to replace the timing belt even though the tippex on the engine cover says it was done just 10k kms ago. I don't trust it. The seller could have written that there himself for all I know...