OBD Connection Failure
 

Vehicle:
2001 A4 1.8t FWD 5spd
completely stock

Problem:

I cannot connect to the on board diagnostics of the car. I have tried using: authentic ross-tech cable & software, Autozone generic obd2 connector and the ebay connectors. I have to pass emissions soon or I cannot renew my registration!

Notes:

I have tried these possible solutions: disconnect/reconnect abs module, checked k-line (.8v kline to ground/i couldnt get a stable ohm reading) according to ross-tech as long as kline is under 12v it is fine. I have tried a complete reset of the vehicle by disconnecting the battery (although I haven't tried connecting to the obd but I'm assuming this didn't help; call me a pessimist lol).

radio was working and problem existed already, however radio is non operative now. I'm not sure how this happened. Nothing on display but is lit up and no sound from any source (doesn't take in cds or tape). Also when I tried to remove the radio to try and reset the fuse, I broke the clips so it is fairly difficult to remove.


Solutions:

can someone point me in the right direction? Please and thank you. Also is there a way to remove the radio without using the din clips?

sorry to resurrect an old thread was this ever resolved my s4 is doing the same thing.

Hey,

Yes, I actually did figure this out. It was an issue with multiple K-Line errors. I had the unlucky situation where my cluster, radio and climate control module were having problems with K-Line.

I would suggest first disconnecting the gauge cluster, as for me that was the easiest. Check with a scan tool. If persists, move on to the radio, then check with scanner (or if you'd like you can go with the ABS module, then radio). Then on to the climate control. Then move on to other K-Line driven equipment. From there you can narrow it down to one, or in my case three, culprit. I hope this helps.

You may also want to do a quick check for battery power on pin 16 of the diagnostic connector on car. Many scanners will not work unless there is power at that pin.
Audi OBD-II diagnostic interface pinout pinout and wiring @ pinoutsguide.com

Question did you physically remove the plug from each of those or did you just pull the fuses. If not did you pretty much rip apart your dash? And my Kline voltage is .34v and pin 16 is 12v my vag com still works just not obd2. Thanks

Yes, I physically took the plugs out. They actually come off without "ripping" apart the dash; they do take some work. I wouldn't consider it ripping apart the dash though. The gauge is held on by a few screws, but to get to it, you have to take the plastic covering around the steering column. For the radio, it's held on by four clips that can be taken off using specialized tools that you insert into the four slits on the radio. I used flat metal pieces that my hardware store carried (I had to shape them out a bit). Once the radio is out, it'll reveal that the temp module is held on by snap clips and screws.

I'm diluting the procedure here, so I suggest you go look for the how-to threads on removal. That's what I did, pretty easy actually.


Your problem might be a little different from mine. I couldn't even connect using Vag tool. But that could also be because of the multiple KLine errors. Maybe you have less systems causing errors that's why your vag tool can still connect. IDK I'm still a noob. Maybe someone who is more knowledgeable can chime in.