OBD II Diagnostic Port Blowing Fuses
 

I have a CEL.on my 2001 TT 1.8T 225 Coupe and ironically (and perhaps related?) the diagnostic port has stopped working and is blowing its fuse. before I bring it to the dealership I thought I'd ask the experts here if they had seen this before.

I read on another forum that the black (vs the blue) colour connector is prone to the pins being pushed back into its housing. Is it possible that the lead that powers the port has shorted with one of the others?

The car is new to me, but has had no electronics mods.

OBD II Diagnostic port
 

Did you have any luck with this problem, I'm getting a " unable to connect " when I attach a code reader to the plug . it looks like it might be the same problem. Also, does the code reader plug have a fuse in line with it ? I asked a dealer that question and they said that there was no fuse.

The dealership wired a bypass to the diagnostic port instead of troubleshooting exactly where the break was as it was going to be very difficult to locate.. This saved a lot of $$ and it works absolutely ok now. They only charged an hour labour.

Make sure you don't have an aftermarket radio, many of the harnesses are wired incorrectly and connect 12 volt to the K-line which messes things up.


Check Ross-tech's site (aftermarket radio problem) for how to fix it.

The other two modules that will block a connection are the cluster and the ABS controller.

Mine has the factory radio .

Unplug ABS and cluster, try it again.