Auxiliary Heater

[Bendling]

Hello

My first post, although I have been a long time avid follower/lurker here and on the 'old' forum.
Thanks to you guys for all the advice freely given. You help keep my ten year old thunderbus running sweet, and hopefully for another couple of years.

Now, I have a problem with my Auxiliary Heater (...really?!).
Or rather, communication with it. I did a scan with my registered VCDS, as I want to fit the parking heater control kit sold on ebay.de.
Module 18 is no longer recognised. The heater works otherwise perfectly, hot gas from the heater exhaust, and warm air in the cabin within five minutes.
Last winter, intermittent white plumes of unburnt diesel from under the car when cold, and weekly fault code clearing kept it running. I have not physically touched or disturbed the heater, and as I said, this year it works perfectly. I've checked all the fuses above the OBD connector, nothing blown. All other modules working correctly, and no faults.
Any ideas as to how I can get 'talking' to it again? Or at least, showing up on VCDS?

[Chrispb]

Hello and

The most common fault when this happens is the large red cable on the heater multiplug has corroded and broken away but as your heater is still working it can't be that one but I would still have a look at both sides of the connector as the problem may be with the data link wire which is pin 5 on the multiplug

[Bendling]

Hi Chris, thanks for replying.
Before I go looking, are the PIN numbers physically marked on the plug?
I hate these connectors, I have a bad habit of forcing too hard when trying to disconnect them, and breaking the locking tab.

[Chrispb]

Yes they are

[attachimg=1]

[Bendling]

Thanks again...
I'll get a look at the weekend and report back.