# Vag Codes: 18010 and 16947? + Where the grounding points?



## Converted2VW (Apr 8, 2009)

Hey all,

As per subject, any guidance as per codes and question above?

What I did:

- Car was working fine.
- Changed intake mani gasket for phenolic spacer (replaced all terminals and cables)
- Tried to change parking light on front passenger side, broke the holder  (on order)
- took it for a drive, drove beautifully and then alternator light came on, NO CODES.

- Tested battery, bad. Replaced battery.
- Took for a test drive, alternator light still on + the two codes above.

Alternator cables and connectors are all fine.
Battery terminals are all fine

Where are the grounding ports in the car?
Any word for these codes?

Thanks guys!


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## deepblueT (Jan 26, 2008)

one of the major points is directly under the battery tray. thats where the negative cable bolts to the frame and then another continues to the alternater...i beleive. there are some straps under the car for the suspension and frame...but i bet your problem is near the battery.


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## Converted2VW (Apr 8, 2009)

Thanks J.

I just cleared all the codes and went for a quick drive (1 mile)

Only the 16947 code came back (Voltage too high)

VagCom measures system voltage at 16.1V...which is way too high.

i need to check all grounds (if I can find them) and then check the alternator.

Any good ways to check the alternator?


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## deepblueT (Jan 26, 2008)

too high? wierd. over grounded maybe? is that even possible?

not sure how to check an alternator. i'm sure theres a way to do it with a multimeter... a good alternator should keep the car running if you disconnect the battery while running. i think... it is a generator afterall, maybe that will tell you, in all my other cars i've every owned...when my battery light came on while driving it was because the alternater stopped doing its job and used up all the juice in the battery causing the battery light to come on because of a dead battery. but at $300+ dollars thats a gamble to just go buy one. 

you have PM from yesterday also.

good luck


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## toy4two2 (Feb 6, 2012)

Ground points

http://www.wak-tt.com/mods/eearthing/engineearthing.htm


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## toy4two2 (Feb 6, 2012)

deepblueT said:


> too high? wierd. over grounded maybe? is that even possible?
> 
> not sure how to check an alternator. i'm sure theres a way to do it with a multimeter... a good alternator should keep the car running if you disconnect the battery while running. i think... it is a generator afterall, maybe that will tell you, in all my other cars i've every owned...when my battery light came on while driving it was because the alternater stopped doing its job and used up all the juice in the battery causing the battery light to come on because of a dead battery. but at $300+ dollars thats a gamble to just go buy one.
> 
> ...


can't be over grounded.

you can drive it up to any autozone or oriely and they can test your alternator for free.


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## Converted2VW (Apr 8, 2009)

I'm gonna have tot ake it off the car first...continuos over voltage will damage the battery for sure.

any ways to test the alternator and regulator at home?

Thanks!


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## Boulderhead (Oct 21, 2012)

toy4two2 said:


> can't be over grounded.
> 
> you can drive it up to any autozone or oriely and they can test your alternator for free.


:thumbup: That's exactly what I would do, and no such thing as having too good of a ground


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## darrenbyrnes (Jan 4, 2005)

toy4two2 said:


> can't be over grounded.
> 
> you can drive it up to any autozone or oriely and they can test your alternator for free.


I had a local VW/Audi performance techs take out all the extra "grounding points" I installed (per the link). They mentioned that having that many grounding points is detrimental to the performance.

:beer::beer::beer:


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## Converted2VW (Apr 8, 2009)

Ok, so here's the progress:

1. Installed new battery (old one was toast). Low voltage error 18010 went away, still have high voltage intermittent code 16947 and alternator light on.

2. Tested alternator, working ok at 14.8V (voltmeter between alternator terminal cable and battery negative terminal).

3. Tested alternator wiring harness and fuse box voltage drop, too high. Should be 0.06V and it shows 0.45V drop. Test by usig voltmeter between alternator terminal and battery positive.

Will check grounding points under battery now


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## Converted2VW (Apr 8, 2009)

Next:

4. Checked grounding point under battery, it was clean and tight! (What a pita to remove the battery box and all that crap!)

5. Checked grounding point on tranny, clean and tight! So grounds are good.

When taking battery box off, noticed a handful of cables that sit between the battery and the airbox that had been smashed by a previous ****ty battery install. One of them is the harness that plugs into the fuse box, i don't know what the other cable is or goes to but i'm in the process of fixing those cables now...

These could be the issue, cables shorting. Will fix and then give it a crank. Btw, i love working on tight spaces!


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## Converted2VW (Apr 8, 2009)

Just to document the fix, i think the smashed cables were the issue.
After fixing them, reinstalled everything, cranked it and took it for a 1.3 mile drive. No alternator light! Yes!

Car feels great now. Tomorrow will scan it and will remeasure the voltage drop between the battery and the alternator for good measure.


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## Boulderhead (Oct 21, 2012)

darrenbyrnes said:


> I had a local VW/Audi performance techs take out all the extra "grounding points" I installed (per the link). They mentioned that having that many grounding points is detrimental to the performance.
> 
> :beer::beer::beer:


Did they elaborate on that theory and how removing ground points helps performance? Other than "too many points of failure" argument I don't see what their logic was based on..


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## Boulderhead (Oct 21, 2012)

Converted2VW said:


> Just to document the fix, i think the smashed cables were the issue.
> After fixing them, reinstalled everything, cranked it and took it for a 1.3 mile drive. No alternator light! Yes!
> 
> Car feels great now. Tomorrow will scan it and will remeasure the voltage drop between the battery and the alternator for good measure.


Good to hear mate, sounds like you had the right tools for the job, which always makes a difference!


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## toy4two2 (Feb 6, 2012)

I found a thread from 2003 on vwvortex about ground points on the TT. I suggest searching for it, about 7 pages of way too much info. Bottom line is although there are no benefits to adding more grounding points, there is no problems with performance, if anything there were dyno posted pics of 5 hp gain from the spark plugs firing better, an extra MPG and much better, stronger radio reception. This with a 8 to 12 ga ground wire upgrade to the areas mentioned.


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## Converted2VW (Apr 8, 2009)

Boulderhead said:


> Good to hear mate, sounds like you had the right tools for the job, which always makes a difference!


Just a multimeter and Vagcom. And they do help to figure things out! Thx for the good word!



toy4two2 said:


> I found a thread from 2003 on vwvortex about ground points on the TT. I suggest searching for it, about 7 pages of way too much info. Bottom line is although there are no benefits to adding more grounding points, there is no problems with performance, if anything there were dyno posted pics of 5 hp gain from the spark plugs firing better, an extra MPG and much better, stronger radio reception. This with a 8 to 12 ga ground wire upgrade to the areas mentioned.


I read through it, very interesting info for sure! Truth is, after finding and checking the grounding points I realized these are pretty sturdy and tight. May look into this down the road though.


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## Converted2VW (Apr 8, 2009)

Ok false alarm. Even though the alternator light went away, the battery was dead when i tried to start it this morning.

Something is drawing power overnight...

Trying to charge the batt so i can try new tests i guess...happy new year everyone!


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## Boulderhead (Oct 21, 2012)

*New Battery?*

Possible you got a bad "new" battery? Have you had it tested?


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## Converted2VW (Apr 8, 2009)

Update:

5. Charged New Battery. Car started right up.

6. Alternator Coltage is good at 14.6V

7. Voltage drop between alternator and battery's positive is still high at 0.24V (was double that) meaning there is still something bad in that harness. Maybe I missed something. May have to take it all apart again.

NOTICED THIS: Now when I give the car gas while parked in the garage, the lights in the aircon system turn off as the revs increase. When the revs go dwn the lights on it come on again. :what:


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## Converted2VW (Apr 8, 2009)

8. Did the good old pull the fuses one by one technique to isolate the system drawing power. The 3 amp draw remained constant! WTF??? (In theory, the current should drop once the defective or drawing system's fuse is pulled...that never happened).

Could this be a bad ECU or a bad ignition switch? (Meaning they keep pulling power after the car has been shut off)...


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## Converted2VW (Apr 8, 2009)

9. Disconnected the alternator wire and retested the static draw, 0.3Amps! which is in the normal range. This means the voltage regulator is NOT GOOD and needs replaced (it is robbing the battery from power when the engine is shut off and is also sending more voltage than necessary)

Ordered it from audi and should have it here tomorrow for $100 (same part is 30 pounds in the UK!).

What a PITA it is to remove the regulator from the alternator!!!

Hopefully this will fix it. We'll see


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## Converted2VW (Apr 8, 2009)

10. Replaced voltage regulator. Measured static draw: 0.3 Amps which is less than 0.5 Amps which means all is good in the world. Also measured alternator voltage while running at 14V, good.
If the battery is alive tomorrow am, all will be good in the world fo sho!


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## Converted2VW (Apr 8, 2009)

End of fix, battery is good this am.


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## deepblueT (Jan 26, 2008)

nice to hear :thumbup:

did you open your river rocks yet?


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## Converted2VW (Apr 8, 2009)

Thx! Just opened one! No rocks, just preciousness! :thumbup:


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