rainman39

Hello all, i have a parasitic drain issue on my wife's 08 Q7. i have read some of these threads and found some good ideas on where to start. Here is what is happening. there is a 6.2 AMP drain on the battery. i investigated and found nothing really until a thread mentioned the passenger side vanity light in the sun visor, a wire under the headliner shorts to ground and causes issues with the interior lights. i fixed that issue , yet the battery drain is still there. my mmi stopped working after this as well,and i'm thinking that something in the mmi system may be the culprit, but not sure because of the significant parasitic drain of 6.2 amp. so far i have tried looking at the alternator, it is Good. someone suggested leaving my meter inline for drain testing the system and pulling fuses one by one until i find the one that causes the drain to drop. i have been through the process of fake locking the doors and letting the car go into full sleep mode but yet al the fuses i have tried so far do not affect the drain. . the battery is brand new and coded. the car will start with the slightest of jump. and will start every-time no issue , until it sets longer than about 6-8 hours. please if anyone or anyone you know can help me shed some light on what it possibly could be. i am at a loss. i also have seen where these systems are very complicated as far as one module working another module and so on , so its hard to trouble shoot one fuse at a time.

Up-it

rainman39

Thank you, Up-it for the response, My Q7 is the S-line, 3.6. it has front and rear proximity system, Bose sound system, MMI3g, heated seats, mirror,steering wheel, external mirrors. dual climate control. rear back up camera with warning system. panoramic sunroof. I do not have a VCDS scan as of yet. i do need one for sure. hope this helps. iam working on it now, i have noticed, even with out the MMI working, there is an audible tick/scratch noise through the speakers, it is very faint and occurs in one second duration every 7 seconds. maybe this can help you in narrowing something down, thank you again.

chingwodapigu

Do you have keyless entry? I've heard that bad door handles can drain the battery. I have been lucky, all my door handles have failed (7 in total, and I've given up trying to keep them working), but for me, it's only the lock button on all of them, so I haven't had issues with battery drain. I think it's more of an issue with the unlock touch sensor, where intermittent signals can keep the car from going into sleep mode. Best of luck with your troubleshoot.

rainman39

Thank you Chingwodapigu for the reply, the car is not equipped with key less touch entry. it has standard entry option. it doesn't have push to start either.

Up-it

rainman39

Thank you Up-It , that is very good information. i will for sure look into this. i have been thinking all along that it having a 6.4amp draw it is going to have to be a rather large piece of equipment. i never suspected the amp, because up until the mmi stopped working the radio worked and sounded great. we have had a very wet past couple of months in my area, like days of non stop rain, it does kinda of coincide with when the symptoms started, i am going to check out you tube on the amp /water damage and then do some more investigation this afternoon. again, thank you for the help. i have been racking my brain.

Jeff Magnan

I had the same issue with a draw from the Bose Amp located behind the right rear paneling, most likely due to moisture damage. The part runs everything (MMI, Stereo, etc.). New from Audi USA the part is over $2,400 USD. I found a company that said they could repair the device for $300 USD. Ship it to them, if they could not fix it, their would be no charge. Sounded like a gimmick, but took the chance. Got it back and everything works great and no drain on battery. The company is Paulison Corporation (https://paulsincorposerv.com). It worked for me, contact them and see. Also, fix the drain issue (just google it and you will see).

Double_Dip_A6

I have a 2007 Q7 and have been chasing a similar issue, but it only occurs when I have not driven for more than 7 days or so. I travel for a living and leave my vehicle at the airport for 4-5 days at a time. It was not unusual for me to hear the battery strain when starting at the airport … however if I left the vehicle for more than 7 days it was almost imposable to start. The dealer struggled to find the answer, but I discovered that the air circulation mechanism in the vehicle was the culprit. The Q7 has a feature where it circulates air on the vehicle periodically and it this drain the battery. simply pulled the fuse if I was leaving for more than 5 days and that has become my workaround. I would start with something that simple.