2012 A6 aux and ac fans "short to ground"
 

Hey folks...

My a6 prestige has 72k on it and I have loved it since I bought it new. Had a thermostat go bad under warranty and that has been the only significant issue. So yesterday I was sitting in traffic for about 20 minutes in 85 degree sun with the windows down. Got a call and rolled up the windows so we could converse and turned on the a/c. Blowing warm and humid. Looked down and my temp was buried. Had a little panic attack since I was in the middle of a ton of traffic, waiting for a train. Had no choice but to shut it down. Much longer story shortened, neither the aux or ac fans were/are functioning. Pulled the VAG codes and got this (along with a couple other minor faults):

3 Faults Found:
6140 - Fan 1 Control Circuit
P0691 00 [045] - Short to GND
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 118277 km
Date: 2016.07.07
Time: 19:05:43

6143 - Fan 2 Control Circuit
P0693 00 [045] - Short to GND
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 118291 km
Date: 2016.07.07
Time: 20:11:14

18198 - Coolant pump
P1B1C 00 [045] - Mechanical malfunction
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 6
Fault Frequency: 1
Mileage: 118377 km
Date: 2016.07.08
Time: 18:14:03

Before I drop $1500 at the dealer, anyone have any thoughts about this one or run into a similar problem? I find it incredible that the one fan failed, the second failed an hour later, and then the water pump failed (which may be a result of the system boiling, not sure). Since i am out of warranty, significantly, I would really appreciate any input anyone may have. I searched the forum but have not found anything with this type of failure for the c7 platform.

BTW, stays nice and cool as long as I am moving.

thanks!

-matt

The US 2011 A6 is a C6. This is the A6 C7 forum. Try posting over at the other forum.

Sorry, typo. this is a 2012.

Ok then, you're in the right place. :)

Have you checked your fuses? If that blew, perhaps both fans are on the same circuit...

Also, have you cleared your codes and rescanned after a short drive to see if the pump fault is still there? Since you seem to be getting cooling when in motion, that would suggest that your pump is still circulating coolant through the radiator, and that the fans are the only real problem.

-Mark

Thanks, Mark. Yes, I am trying to determine where the fuse(s) for the fans are. I think they are under the hood maybe under the plenum, but I want to get some confirmation from a more knowledgeable forum member before I start taking things apart. I know the fuses are not in any of the three more accessible panels (dash left/right, trunk). I did save the codes and then cleared. The pump code stayed clear, and the pump seems fine, but the fans stayed shorted. Obviously not driveable during summer rush hour, so if I dotn hear back on the fuses soon, I'll probably need to just get it to the dealer (I also need the airbag recall fix and the 75k service).

thanks!

-m

In case anyone comes across this thread, I have resolution. Found the fuses, both 40A, both blown. Replaced with new 40 amp fuses and both fans operating properly, still working after about an hour. Maybe just a perfect storm of electrical overload, I literally got a call on bluetooth, closed the sunroof and auto-up on the windows, turned on the a/c, and had been sitting stationary in traffic in the heat for 15 minutes. Going to reset the codes with vag/com and see how it goes. If anyone needs help finding these fuses, let me know. They were not in the e-box under the ECM and washer reservoir. They were in a separate panel under the crossmember. Just about the most difficult location possible.


https://cimg6.ibsrv.net/gimg/www.aud...937d23bf8f.jpg

Two 40 amp fuses blown. Had to buy at the dealer.



https://cimg7.ibsrv.net/gimg/www.aud...6846f61af2.jpg

panel is under the plenum cover and crossmember in the center rear of the engine compartment.

Thank you for sharing your findings with clear pictures.
Book marked for future reference.
It is hard to imagine both fuses were blown at the same time.

Thanks for the update. Wow, talk about a top secret hiding location!!!

Keep your fingers crossed that you don't have an intermittent short somewhere and the fuses open again. It's hard to believe the fuses would fail just by closing the windows, turning on the A/C, and answering your phone in traffic. This is a first I've read of those fuses failing in a C7 until now. Best of luck that you're in the clear.