# K-line reading 12v Need help!!



## Mnomm (Sep 28, 2010)

*K-line reading 12v Need help!! (Pics inside)*

I have a 2001 wolfsburg jetta 1.8t 5spd with some major issues lately. The problem i'm most concerned with is not being able to read any of my codes. And i know your supposed to post a log of your autoscan for any help, but thats not possible for me to do unfortunately. 

So heres the problems: on the instrument cluster my airbag light, ABS, and ASR (traction control, and Check engine are all on. The check engine just happened recently and before it i still wasn't able to connect. 

To go along with that is a series of other problems, that im not quite sure if their related at all but maybe they'll help. As of right now i'm getting about 17 miles to the gallon, and i never go over 3k rpm so this should not be happening from a 1.8t with 70,000 miles. And the other more strange problem is sometimes when i'm driving my doors will randomly unlock, or one of my windows will roll down an inch or so. And no i'm not bumping the controls on the door, its been happening a lot lately and starting to freak me out

I do not have an aftermarket head unit or anything electrical for that matter. I even disconnected my k-line wire from the stock head unit and it still did nothing. I tested between pins 4 and 7 on the OBD-II socket and i got a reading of 11.67, much higher than it should be I do have a Bentley manual but i'm only mediocre when it comes to reading schematics. 


I understand there are many problems going on here and may be difficult to follow but i appreciate all the insight. Any ideas where i should start?


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## Mnomm (Sep 28, 2010)

anyone?:thumbup:


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## [email protected] (Jun 5, 2002)

Unplug stuff one at a time and try to scan remaining items. Start with ABS, then Engine, etc.


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## Mnomm (Sep 28, 2010)

If i do find which module it is what does that tell me? That its a bad part, or the wires leading up to it are bad?


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## Mnomm (Sep 28, 2010)

.


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

WOW! That looks like the Airbag module. If you decide to attempt to unplug that thing please do so with the battery disconnected. 

Keep in mind those Airbags and tensioners are explosives and even if completely unplugged any power supply through incorrect/shorted/melted wiring could cause deployment. I would recommend sending that to a shop or dealer for the proper repair, depending on the extent of damage that harness may need to be replaced.

Was this caused by lack of underside heat-shields or the incorrect exhaust system?


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## Mnomm (Sep 28, 2010)

Dana @ Ross-Tech said:


> WOW! That looks like the Airbag module. If you decide to attempt to unplug that thing please do so with the battery disconnected.
> 
> Keep in mind those Airbags and tensioners are explosives and even if completely unplugged any power supply through incorrect/shorted/melted wiring could cause deployment. I would recommend sending that to a shop or dealer for the proper repair, depending on the extent of damage that harness may need to be replaced.
> 
> Was this caused by lack of underside heat-shields or the incorrect exhaust system?



My driver seat airbag already blew randomly when i wasnt even doing anything. I was reading the voltage between 4 and 7 and the next thing i knew it was off. So im not sure what went on there but this module couldnt have happened from that because i didnt smell any burnt wires/plastic after that. Im assuming it happened with the previous owner because in the 6 months ive had the car nothings ever smelled. Im going to look for a new airbag module before i even bother touching this thing and when i do ill be sure to have the battery disconnected for quite some time before messing with it

I just want to know what caused this, i have a stock exhaust and nothing out of the ordionary so something along the lines shorted and caused this...

When replacing the module do i have to get the exact same number, or is there some variant that i can get?


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## vwemporium (May 27, 2002)

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THIS SOLAR SYSTEM IS IN DANGER OF A BLACK-HOLE!
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I CAN BE FOUND VIA THIS DHD STAR-GATE ADDRESS......
http://forums.ross-tech.com/member.p...European_Parts


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## Mnomm (Sep 28, 2010)

vwemporium said:


> Slight case of short latent to ground. YIKES.
> 
> GREAT PIC
> 
> ...


 Nope theres no water anywhere, and I never had any other sort of water damage which is why this blows my mind on how this could possibly get this bad. Im going to take it into the dealer tomorrow and see what they have to say about it and see what they would do to fix this 

Just a question for thought, if and when i cut this out, if this is the only problem, theoretically this would be the same as pulling the plug on the module. And if this does turn out to be my only faulty area i should be able to use my VAG COM without getting a short?


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## trouble1mk (Sep 25, 2005)

Mnomm said:


> My driver seat airbag already blew randomly when i wasnt even doing anything. I was reading the voltage between 4 and 7 and the next thing i knew it was off. So im not sure what went on there but this module couldnt have happened from that because i didnt smell any burnt wires/plastic after that. Im assuming it happened with the previous owner because in the 6 months ive had the car nothings ever smelled. Im going to look for a new airbag module before i even bother touching this thing and when i do ill be sure to have the battery disconnected for quite some time before messing with it
> 
> I just want to know what caused this, i have a stock exhaust and nothing out of the ordionary so something along the lines shorted and caused this...
> 
> When replacing the module do i have to get the exact same number, or is there some variant that i can get?


 NEVER test the air bag with volt meter, it will blow the bag. just think about how volt meter works, you will know why.


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

Mnomm said:


> When replacing the module do i have to get the exact same number, or is there some variant that i can get?


 Yes you will need the identical part number or its newest replacement from the VW dealer. Due to the severe damage and bag deployment I would suggest having them install and code the new module.


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## Mnomm (Sep 28, 2010)

trouble1mk said:


> NEVER test the air bag with volt meter, it will blow the bag. just think about how volt meter works, you will know why.


 
On Ross tech's website it states to test between pins 4 and 7 with a volt meter to diagnose the k-line problem


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## Mnomm (Sep 28, 2010)

Dana @ Ross-Tech said:


> Yes you will need the identical part number or its newest replacement from the VW dealer. Due to the severe damage and bag deployment I would suggest having them install and code the new module.


 
Okay thanks for the help:thumbup:


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## jetta 971 (Jul 25, 2009)

Mnomm said:


> My question is, and what i'm worrying about is when i fix this is it going to happen again because something else was originally shorting, or if this was initially the main problem
> 
> Any insight?


 This looks to me that someone in past was welding something like exhaust under car and did this to air bag module,or after market down pipe will do this to module.We all know that airbag module is mounted right above exhaust. I don't think this comes from being short, because the bottom of airbag module and label would not burn, it would burn wires and connector. 

You will need new harness as well, because you can not repair air bag wire due to resistance in wires may being high or low.


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

Mnomm said:


> On Ross tech's website it states to test between pins 4 and 7 with a volt meter to diagnose the k-line problem


 The mentioned testing is done at the a DLC, not a control module: http://www.ross-tech.com/vag-com/aftermarket-radio.html 

I highly doubt the DVOM testing at the DLC caused the deployment, the K line sounds like it was already shorted to power and the K line does not trigger deployment signals. I believe the melted module caused the deployment.


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## Mnomm (Sep 28, 2010)

.


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

Mnomm said:


> Regardless of what caused it, it sure scared the S*ht out of me!


 Yeah, I wasn't downplaying that at all! That is a very serious thing and could result in serious injury or death. 

I was defending your use of a DVOM on the DLC, I think the other poster thought you were probing wires at the Airbag module. That would not be cool and could cause bag deployment.


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## Mnomm (Sep 28, 2010)

Dana @ Ross-Tech said:


> Yeah, I wasn't downplaying that at all! That is a very serious thing and could result in serious injury or death.
> 
> I was defending your use of a DVOM on the DLC, I think the other poster thought you were probing wires at the Airbag module. That would not be cool and could cause bag deployment.


 Yea im not going to mess with that thing at all. Im trying to figure out the best and *safest* way to remove this. Is unplugging the battery and waiting a far amount of time enough to make the system safe to work on, or is there other precautions that should be taken when removing this?


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## cuppie (May 4, 2005)

Looking at that melted mass, I don't think you're going to be removing it by the 'normal' means (unplugging it) - you're going to be removing it with wire cutters. 

My "I'm a dealership tech" recommendation: 
Disconnect the battery, and wait a 'fair amount of time' (generally, everything will bleed power off after a few minutes.) 
Cut the harness, one wire at a time, a few inches into the non-melted part of the harness. Stagger the cuts in such a way that bare ends can't contact each other. Minimally, cut all of the power, ground, and bus lines, and individually tape each off. 
For added safety, remove the airbag system fuse(s) from the vehicle.


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## Mnomm (Sep 28, 2010)

cuppie said:


> Looking at that melted mass, I don't think you're going to be removing it by the 'normal' means (unplugging it) - you're going to be removing it with wire cutters.
> 
> My "I'm a dealership tech" recommendation:
> Disconnect the battery, and wait a 'fair amount of time' (generally, everything will bleed power off after a few minutes.)
> ...


 
Sounds pretty sufficient to me. If this all goes well i think im going to look for a job as a bomb technician, it sure feels like it!:laugh:


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## Mnomm (Sep 28, 2010)

Well today i cut out the old module and got the new one in, and low and behold..no more short at K1!! 

Its a relief knowing i can now see what is going on in my car 

Thanks for all the help guys:thumbup::thumbup::beer::beer: 

update: Well when i was cleaning out that spot where it goes today i pulled this out... 
 

Which if some of you didnt know, came from one of these... 
 

Anyone else starting to think this wasnt just an accident??:banghead:


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## Mnomm (Sep 28, 2010)

Would anyone happen to know if the K-line is needed at the airbag module. 

I used my old harness (6Q0) with a new connector, and the new one (1C0) does not have the K-line. The VW dealer said this part was the replacement, so why would an exact replacement not have a spot for the K-line?


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## jetta 971 (Jul 25, 2009)

Mnomm said:


> Would anyone happen to know if the K-line is needed at the airbag module.
> 
> I used my old harness (6Q0) with a new connector, and the new one (1C0) does not have the K-line. The VW dealer said this part was the replacement, so why would an exact replacement not have a spot for the K-line?


 I don't know what you mean buy saying you don't have K-line , but if you have connector with 75 pins, here is the pin schematic: 

Pin-54= K line( gray/white) 
Pin-74= Can High( orange/black) 
Pin-75= Can Low(orange/brown) 

Only once that did not have K-line was 98-99.5 none Can cars, and they have 50 pin connector. 
Also as you have update version of Airbag module , you may need to replace Crash sensors. The old one it will not work with update airbag module. 
If you get codes 01221,01222,01738,01793 side crash sensor -no or incorrect basic settings 
you will need replace crash sensors.


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