# K1 short to ground need some guidance



## jasman19 (Jun 26, 2008)

I have an 01 S4 and previously I haven't had any issues connecting Vag-Com. I was going to reset my service light and check a code, but I recieved a no response from controller error when I tried. I then ran through the options menu in Vag-Com and it says that I have a short to ground on K1. I've been through the bentley looking for a decent wiring diagram to see which wire is K1 on the diagnostic plug, but all I can find is that terminal 7 on the T16 connector is described as the k-line wire. There are also two ground wires, the 12+ battery power wire and two others that I can't find anything on. There is a black/blue wire on terminal 1 and a black/white on terminal 13. I did a continuity test on the k-line wire to see if it was grounded, but it is not. Any help from here is appreciated.


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## jasman19 (Jun 26, 2008)

I did some digging around and found this useful link for troubleshooting aftermarket radios:

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

The link had a much better pin out diagram than the ones I've seen elsewhere. Pin 7 is the K1 wire and Pin 15 is the K2 wire, so I'm having issues with the green wire on Pin 7.










When I get back to my shop tomorrow I'll run my multimeter on the connector and see what I come up with. I did take my radio out, but the guy who put it in spliced into the harness and didn't use adpapter style harnesses. I completely unplugged the radio and I noticed no change with the Vag-Com status.

I also found a past post that said any module on the car can ground the K1 wire, so I guess if I can't come up with anything else I'll just systematically unplug each module (minus the airbag module) until I get a green light on my Vag-Com cable.


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## Dana @ Ross-Tech (Sep 15, 2009)

jasman19 said:


> I also found a past post that said any module on the car can ground the K1 wire, so I guess if I can't come up with anything else I'll just systematically unplug each module (minus the airbag module) until I get a green light on my Vag-Com cable.


Yes, any module that is diagnostic capable could short the K line so start with the radio K line (since it is probably hard wired at the radio mess) and try the ABS next, working your way through all installed modules.


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## jasman19 (Jun 26, 2008)

Got a chance to check out the car. The problem isn't the radio or the abs, so do I have take my car apart to pull the plugs on each of the modules? Which modules do I need to be concerned with?


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## Uwe (Jan 16, 2000)

Before you tear your car apart, double check that your interface isn't on the fritz. Plug it into any other car with an OBD-II port (doesn't have to be a VW or Audi) and do [Options] -> [Test]. If it says "K1: OK" on that car, but "K1: Short to Ground" on your car, then you can be sure the problem is your car. OTOH, if it says "K1: Short to Ground" on other cars as well, then your interface is defective. 

-Uwe-


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## jasman19 (Jun 26, 2008)

Thanks for the advice. I did check the interface and it works on other cars. Is there an easier way to eliminate the modules than pulling the car apart?


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## Uwe (Jan 16, 2000)

I suppose you could apply a hard +12V to the K-line and try to determine where the resulting smoke comes from. 

There are also highly specialized electronic tools called "Current Tracers" which might help you track this down, but I doubt that buying one would be cost-effective for one-time use.

-Uwe-


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## stan067 (Feb 25, 2010)

Most V.W. & Audi K-line go to a common bridge connection above fuse card. Don’t hold me to that on an S4! Pin 7 of DLC goes to this bridge and all other modules go here also. 1 wire for each module the car has and 1 for the DLC. It’s just a connection point or splice. This bridge will have a lot of single wire plugs. Like I said 1 for DLC and 1 for each module in the car. I think the DLC wire is green single wire at bridge. The modules are different colors 3 green& blue, 3 green & red, 3 green & brown, 1 green & brown, 1 green and purple. That’s like 12 single wire plugs. Finding this bridge or connection point is the easiest way to go because you can disconnect one wire at a time to disconnect a module and check for log in. Also post the exact year, make, model and engine. Good Luck


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## stan067 (Feb 25, 2010)

Uwe was totally joking about the power and watch for smoke! But don't laugh I have actually seen old timers do this in old cars and think they can still do it in new cars. Good Luck


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## Uwe (Jan 16, 2000)

> Uwe was totally joking about the power and watch for smoke!


Indeed, I was.

-Uwe-


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## [email protected] Parts (Nov 27, 2006)

:::::ALERT FORUM ACTION EMERGENCY MESSAGE:::::

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U 

Just email or PM John [email protected] as to why I have chosen to do this for a modification answer to these posts.....
Ultimately this is his fault for how the account was handled.
[email protected]
You could say I feel insulted and abused..........


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## jasman19 (Jun 26, 2008)

Nice... I went through the fuses before I pulled the radio and they checked out. I'll see if those connectors are above the fuse panel, and if they are, that would save me a lot of time. I'm just trying to avoid tearing my whole car apart to find which module is the show stopper. If I can't find the connectors then I'll check to see if my Home Depot has the tone tester you mentioned. One way or the other I've got to get this fixed because its only a matter of time before I get a CEL and then I'll be screwed.


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## [email protected] Parts (Nov 27, 2006)

My money bet its the ..............


:::::ALERT FORUM ACTION EMERGENCY MESSAGE:::::

THIS POST MOVED/VACATED BY JACK TO PROTECT CONTENT FALLING INTO THE GAPING HOLE OF THE VORTEX

IT SEEMS NO GOOD DEED GOES UNPUNISHED!

http://www.youtube.com/watch?v=HaoySOGlZ_U 

Just email or PM John [email protected] as to why I have chosen to do this for a modification answer to these posts.....
Ultimately this is his fault for how the account was handled.
[email protected]
You could say I feel insulted and abused..........


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## jasman19 (Jun 26, 2008)

Lol... just trying to avoid unnecessary work. My car is a 6 spd so no trans ecu, and I had the cluster rebuilt about 2 months ago (still had the same issue before). Right now I'm finishing up an exhaust swap on it then I'll start messing with this issue again. Been a fun little swap so far, but it takes some time. I couldn't see doing it without a lift, so props to you guys that have.


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## jasman19 (Jun 26, 2008)

Got the exhaust finished up last week, and I finally got some time to check if there was a bunch of connectors to k-line above the fuse box. If I follow the k-line cable harness it basically heads into the large main harness that is above all the relays. There isn't anything obvious that I can see would be the connectors (described before). It makes sense to me that there should be some connectors some where, but I'm not sure where. I'll pull the cluster and see what happens, after that I'm not sure which one should be next.


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## jasman19 (Jun 26, 2008)

Alright, I pulled the instrument cluster and got a green light on the vag-com connector. I couldn't communicate with anything in the car though, so I plugged the instrument cluster back in. I can now communicate with all the modules except the engine control. I switched the ignition off and back on again, and now I'm getting a red light. Obviously the ecu is grounding out the k-line, but is this because of the APR chip that I have or is something else jacked up? How can I fix this?


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## id04265 (Apr 4, 2011)

*status?*

I have simular K1 short to ground on a 98 A6 but not having any luck tracking it down...did you resolve your issue? what was meant by the instrument cluster?

thanks


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## jasman19 (Jun 26, 2008)

Yeah I finally tracked down the problem. The issue ended up being the climate control unit and I found the best way to track down this issue is by doing an amp draw test off the battery. Disconnect the positive cable from the battery and use a multimeter set to display amps. Connect the probes inline between the positive cable and the positive battery terminal. At this point you want check the amperage and I began pulling one fuse at a time until I found which system was pulling the amps. 

I isolated the amperage draw to the the climate control circuit, and then disconnected the climate control unit from the car. Once the unit was disconnected I checked the amp draw to verify it had dropped to an acceptable level (.3 amps after the modules settled down). With the module disconnected I tried to connect to my car with VCDS and I had no problems. At this point I found a used climate control unit and replaced my bad unit (no more problems now)


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## stan067 (Feb 25, 2010)

Good new thanks for posting the fix after so long. 
Good Luck


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## AhmtOzdmr (Apr 22, 2016)

Thanks.


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