VAG-Com - Revisiting communication issues, K1 short to ground, K2 OK

[redneck truck]

I have had the same intermittent problem for about a year and a half and I can't seem to nail down what's causing it: VAG-Com will not communicate with any control module, and when entering Options\Test Connection, I get Status: Questionable; K1: Short to Ground; K2: OK.

I have only seen this on my car and have used the same cable and port on a dozen different cars, so I know it's the car.

- Radio is stock, no aftermarket electronics.
- Transmission wiring harness was cut behind the firewall when I did the manual swap, removed the TCM.
- While having the issue, disconnected ECU, cluster, radio, HVAC control head, ABS pump, didn't fix anything.
- Inspected the OBD connector, looks fine to me.

So, I'm at a loss. There are probably lots of modules on that communication bus, but I removed all the ones I could think of hoping one of them was causing the issue. Any thoughts on this would be most appreciated.

[audifirst]

K1: Short to Ground
you need to trace wires , it is either cut or pinched somewhere.. perhaps when you did the conversion..
did you test the vagcom in another car ?

[redneck truck]

Yes, I've plugged it into my 3 other VW cars and several other cars as well. Suppose I better start pulling up carpet and figure out where it's shorting.

[8520]

01? I wonder if you're still running k-line data.

I would check for power and ground at the obd connector with a multimeter.

[redneck truck]

Communication is back! Seriously no rhyme or reason here. I let the car sit, turned off for 2 hours and now it works again. If the problem is wiring, one would expect some sort of mechanical input would be necessary to toggle the problem, but I literally walked away with it not working and walked back in to it working again. Maybe a relay is sticking? Maybe a module is shorted internally?

[8520]

I would lean towards the latter.

I wonder what k1 and k2 are.

[redneck truck]

communication lines that run to all the modules, as I understand. Which means the short could be anywhere.