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IM OUTTI
09-03-2014, 11:09 AM
Used vag com to scan my check engine light and it read the code listed in title. Exactly what does it mean and have any of you guys had this problem. Also im running thru fuel as if the tank had a hole. Im alsl hearimg a occasional repated thump in the rear when driving. But if I let the car run till warm the thumps dnt exsist. Im lost and need answers. Is the car safe to drive?

rollerton
09-03-2014, 11:39 AM
Evap system pumps the fuel-tank vapors up to the engine to be burned, rather than venting them to the atmosphere. You've probably got a fitting that came off. And yes, it can result in poor fuel economy- say if the EVAP line is open and the engine is getting "fresh air" instead of fuel vapors then it may be acting as if you have a vacuum (intake) leak; in which case the ECU could enrich the mixture to compensate . The hissing could be the Evap pump trying to do it's job.
I don't think there's any real immediate danger from driving it...but might want to have someone check it out sooner than later.

IM OUTTI
09-03-2014, 11:48 AM
Wow. Thanks alot for that info. I was thinkin somethimg more complicated like a canister purge regulator valve. But ill have all the hoses checked. Any idea where the evap lines are in our cars

maga4
10-02-2015, 05:54 PM
Hey all, having the same thing show up via vag-com. Only difference is mine says "Very Small Leak Detected - Intermittent" for the MIL. Don't think it's the gas cap as it had been about 180 miles and 3 or 4 days since I last filled up. I'm not sure how the date and time work for this module, but interestingly it says it happened 10/1 when the light came on today, 10/2 (maybe that was the first fault?).

The only thing new this morning when it went off is that it was the coldest morning this far (~45*F), but not sure that would impact anything.

I figured I would re-click/re-seal the gas cap and clear the codes, but wanted to put it out there in case anyone had any other thoughts.


Address 01: Engine (CCA) Labels: None
Part No SW: 4F1 910 551 D HW: 4F1 907 551
Component: 3.0l V6 TFSI 0020
Revision: --H06--- Serial number:
Coding: 0105000A190F0120
Shop #: WSC 02325 785 00200
VCID: 244DF085E71EE21E19-8070

1 Fault Found:
001110 - EVAP System
P0456 - 000 - Very Small Leak Detected - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100001
Fault Priority: 4
Fault Frequency: 2
Reset counter: 255
Mileage: 69435 km
Time Indication: 0
Date: 2015.10.01
Time: 06:38:49

Freeze Frame:
Lambda: -3.0 %
Temperature: 24.0C
Temperature: 84.0C
Speed: 50.0 km/h
Time: 332.8 s
CAT Temp.: 560C

Readiness: 0000 0000

I did find this thread, which was helpful, but wondering if the fix is DIYable for the 3.0T as well as the 3.2? http://www.audizine.com/forum/showthread.php/486913-EVAP-Purge-Valve-Replacement-Cost

Thanks!

ManyAudis
10-03-2015, 06:45 AM
I have had this happen a couple of times in my car, years apart. In both cases it was on days when the mornings were quite cold but then it warmed up a lot during the day and in both cases the fuel tank was low. On days like this the air in the fuel tank is very cold in the morning and then in the evening after sitting in the parking lot at work in the sun and it has warmed up the air expands and pressurizes the tank. The pump on the purge system is rather small and the Audi documentation states that this pump will run for a short period and then the tank pressure is tested. If there is some vacuum but it is not below some expected vacuum level it reports a small leak in the evap system. I think on these days when the tank self pressurizes a lot the pump just cannot remove enough of the gas vapors before the pressure test is performed. In both of my cases I reset the fault and it did not come back.

Your case looks different because the fault tripped at 6:38 in the morning before fuel tank warmed up. I would still recommend examining the fuel cap and rim of the tank and make sure there is no contamination, re-seating the fuel cap and resetting the fault. If it comes back then replace the purge valve.

maga4
10-03-2015, 08:31 AM
I have had this happen a couple of times in my car, years apart. In both cases it was on days when the mornings were quite cold but then it warmed up a lot during the day and in both cases the fuel tank was low. On days like this the air in the fuel tank is very cold in the morning and then in the evening after sitting in the parking lot at work in the sun and it has warmed up the air expands and pressurizes the tank. The pump on the purge system is rather small and the Audi documentation states that this pump will run for a short period and then the tank pressure is tested. If there is some vacuum but it is not below some expected vacuum level it reports a small leak in the evap system. I think on these days when the tank self pressurizes a lot the pump just cannot remove enough of the gas vapors before the pressure test is performed. In both of my cases I reset the fault and it did not come back.

Your case looks different because the fault tripped at 6:38 in the morning before fuel tank warmed up. I would still recommend examining the fuel cap and rim of the tank and make sure there is no contamination, re-seating the fuel cap and resetting the fault. If it comes back then replace the purge valve.


Great info, thank you!

The clock was off a bit, it was actually about 540am and about 45 degrees. I had driven for about 10 minutes average 35mph at low RPM so it could potentially have warmed a bit.

I re-seated the fuel cap and reset the codes. Was good for a quick drive around (~5 miles) so perhaps it was just a fluke or a one off at this point. If it comes back again I will definitely look to replace the purge valve.

Hopefully it doesn't give any problems fueling or starting after fueling. Thanks again!