Probably the wrong forum sorry.

My diagnostic port is not communicating with the faultcode reader my mechanic has. Any ideas whats up? I have a TT dash so it could literally be anything...

Start with the basics. does the car have an aftermarket radio?

http://www.ross-tech.com/vag-com/aftermarket-radio.html

Have you checked your fuses?

It does have an aftermarket radio -that guide is excellent thank you!

Ive had a quick look at the fuses but other than a multimeter and about 2 hours wasted Im not sure how Id check they are all functioning?

No fuses are gone and the radio has been removed, still nothing. On the diagnostic port I have 10 wires missing and further up the loom there are 10 grey and white wires with the ends cut off. I am told that this is the CAN bus and it is not needed for the diagnostic port to communicate with the code reader. I have the following pins connected in the diagnostic port - 1, 4, 5, 7, 13, 16.

Anyone any ideas?

Is he using VAG-COM?  If so, have him do an [Options] [Test] and report what the K-line status is. The wires you have listed are in the correct positions.  That is, there should be wires in all of those positions.

You may have a faulty module that is tying up the diagnostic buses.  To troubleshoot, you could start unplugging modules to see if the tool will communicate. 

Beyond this, can't really help without more information from the scan tool.

Thanks thats helpful, When you say unplugging modules, what exactly do you mean?

Sorry! Im new to all this!

James, the electronic modules in the car share the diagnostic "bus".  That is, they all communicate on the same wire.  If the communications port of one control module has failed, it can "hang" the bus by not permitting any other device to talk on the common wire.

So, my suggestion is to eliminate one module at a time to see if the diagnostic tool can "talk" to any module in the car.  By process of elimination, you can find which module has things hung. 

Make sense?

Yeah that makes sense. How would I do this? Just unlug the various modules completely?

That is what others have done. 

Again, my recommendation is to have access to VAG-COM, and to start by doing the test I suggested so that you know one of the diagnostic buses are hung.  Right now you do not know what the problem is.  You only know that the tool your mechanic used could not communicate. 

Once you know the true symptom, you can begin troubleshooting the wiring/the modules to see what is hanging the bus.  To do so before knowing is an utter waste of time and may result in more problems. 

Get access to VAG-COM and perform the test before you do anything else.

Righto mate, thanks for the help - you're a lifesaver!