0456 error code
Thread Starter
AudiWorld Junior Member
Joined: May 2018
Posts: 11
Likes: 0
0456 error code
I'm new owner of Q7 and have the vehicle for 2 months now. After few weeks of city driving CEL came on and I connected OBD reader and got code P0456 (small leak). I tighten the fuel cap and cleared the code. After about ~60km the CEL came on again. This time I didn't clear the code and kept driving with CEL on. One time I got a message on the dash "Close tank flap". After reading few posts on here I decided to purchased new rubber seal for the fuel cap as I suspected that's where the problem is. I replaced the fuel seal and I cleared the code again and after about ~50-60km the CEL light came on again and few km after the "Close tank flap" warning.
Just another info to add, I'm not sure if this has to do with this problem or not. I filled my vehicle twice since purchasing it. The first time I filled it I didn't really top it off and next 700km the CEL didn't come on. The second time at fuel up I filled it to the top past the pump clicks ( about ~99L, 26gallos of fuel) and after this fuel up is when the CEL problem started to occur.
Is my next step to replace the whole fuel cap? What else could be wrong?
Just another info to add, I'm not sure if this has to do with this problem or not. I filled my vehicle twice since purchasing it. The first time I filled it I didn't really top it off and next 700km the CEL didn't come on. The second time at fuel up I filled it to the top past the pump clicks ( about ~99L, 26gallos of fuel) and after this fuel up is when the CEL problem started to occur.
Is my next step to replace the whole fuel cap? What else could be wrong?
AudiWorld Member
Joined: Oct 2017
Posts: 51
Likes: 0
From: Denver, CO
There seems to be a couple different versions of that code and you need a VAG cable and software to decode it. Audi has a TSB for newer cars on this: https://testing-public.carmd.com/Tsb...110838/A011651 which seems to indicate a known failure in the pump used to check for leaks. (Hilarious, you can't make this stuff up... The pumps that is used to find leaks is known to leak!) It's possible to be anything in the EVAP system however. I'd agree replacing the gas cap might be a good next course of action but that error worries me as I think that refers to the flap, not the cap. Check the sensor on that perhaps?
Thread Starter
AudiWorld Junior Member
Joined: May 2018
Posts: 11
Likes: 0
Thanks for the info. Can you point me to the sensor on the flap? What am I supposed to be checking? New OEM fuel cap is $90+shipping so if I can solve this without purchasing it that would be great.
Thread
Thread Starter
Forum
Replies
Last Post
cparke
A4 (B5 Platform) Discussion
2
Dec 27, 2008 06:16 AM
Fastscirocco
Audi Original "S" Cars
5
Feb 20, 2008 11:59 AM
1997Cabrio
Audi 90 / 80 / Coupe quattro / Cabriolet
3
Jan 21, 2006 07:36 AM
Sloooo4esT
Audi Original "S" Cars
2
Jan 18, 2006 03:42 PM
Tongpo~Dr. Evil
A4 (B5 Platform) Discussion
2
Jan 28, 2004 02:01 PM
