Parasitic Battery Drain

[firstuser]

2002 A4 1.8T. I've searched the threads and got good information that has gotten me far in solving this but I haven't completely solved it yet. My car has a parasitic drain where if I leave my car sit for a week or less the battery is dead. I replaced the battery twice so I know its not the battery. I can also jump the battery and it starts right up. If I drive it everyday I don't have any issue. Everything is factory and stock, no aftermarket radio, no hardwire radar detector etc. I've owned it since new (366,000 miles). I pulled fuses 24 (CCM), 38 (CCM), and 39 (Radio). I don't think it has to do anything with the radio. When I pull all those fuses the issue does not happen. With the fuses back in I hook it up to a voltage meter and didn't see any drain. I decided to take it to an independent mechanic that deals with German cars. They tested everything and confirmed no unusual draw as well and said everything looked fine so they could not find anything wrong. Nice bill for telling me that. They also had my car sit for two days and the battery did not go dead. I got my car back yesterday and I'm not convinced it's fixed though. From reading on here in another post from years ago someone said to try two things. Lock the doors with the keypad and check all doors from outside and trunk to see if they are locked one by one. I did that and everything was locked. Also they said start the car and from the inside open each door one by one and see if the door shows on the dash as opened. I did that and all doors worked except when I open the front passenger door from the inside it does not show on the dash as opened, nothing appears. Could this be why the battery is draining? One other thing when I lock my doors with the keypad there is no chirp. It's been doing that for a couple years now I just can't remember if it did that before or after the battery drain. Maybe its the alarm battery in the trunk causing issues with the chirp and I have two separate issues. Thanks,

[Turbo510]

You are doing a lot of guessing, unfortunately. You pulled three fuses, and the battery didn't drain. You put them all back, and it drained. You need to know which fuse is conducting the unwanted current. If you put your DMM in current-mode, probe across each of those fuse contacts (fuses removed). One fuse location will have significantly more current draw than the others, meaning you can probably disregard the other two.

Now, to check those fuses, the driver's door will have to be open. You will need to manually flip the latch into the "closed" position so the electronics acts like all doors are closed. But... put a sign on your door to remind you to unlatch the door before you slam it closed!

[firstuser]

Thanks Turbo I will give that a shot. Yeah when I put the three back in was when I figured I take it to the shop and see if they could figure it out but that is a great idea you gave me. I'll report back. Thanks!

[4xaudi]

Mine is being caused by fuse 38(CCM). With the fuse in the current draw is .6amps. Once I remove it the drain drops to .012 amps.

[EuroxS4]

Time to hook up a dvom to the car and watch it as you pull fuses to see where the draw is coming from. Check wiring in the hinges most likely broken. Normally these cars need to havea draw of less or equal to no more than 0.030amps anything above is no good.

[Halvis]

Check the brake light switch. Mine got stuck on and the brake light was on over night. difficult to detect during summer time when it is almost bright around the clock.


Sent from my iPhone using Audizine Forum

[Turbo510]

Check the brake light switch. Mine got stuck on and the brake light was on over night. difficult to detect during summer time when it is almost bright around the clock.

Very common, and exactly what happened when my daughter owned this B6.

[maurizio]

check voltage drop across fuses

[b6_nikola]

im having the same issue, same fuses causing the problem. a few weeks back when i was putting the radio fuse back in there was a spark. 3 days ago when i was putting it back in there wasnt lol

[promet]

hi, when you say the brake light ' switch ', what component are you referring to? where is it located please?

[EuroxS4]

hi, when you say the brake light ' switch ', what component are you referring to? where is it located please?

Brake light switch is under the dash on driver side dash. It sits on a bracket at the top of the brake pedal. However if you had a bad switch I would assume you would have a fault or the brake lights would be on and drawing way more than 500ma.

[promet]

Thanks!

[iowa_gts]

Yes exact same thing is happening for me as well can’t figure it out


Sent from my iPhone using Audizine

[iowa_gts]

Let us know what you find out !


Sent from my iPhone using Audizine

[firstuser]

I still haven't been able to figure it out. The issue went away for a few weeks and then just returned. Sadly I might be getting rid of my A4. I love the car and although I shouldn't, I do have an emotional attachment to it. I bought the car new 20 years ago brand new and put on 367,000 miles. If I could just figure this out and my no heat issue it would be good. Or at least figure out one of them. Every time I take it to a mechanic to check out they don't find anything and I've been to different mechanics. If I could find someone to take a look on the east coast (Philly, NJ, DE area) that would be great.

[Darepoole]

I still haven't been able to figure it out. The issue went away for a few weeks and then just returned. Sadly I might be getting rid of my A4. I love the car and although I shouldn't, I do have an emotional attachment to it. I bought the car new 20 years ago brand new and put on 367,000 miles. If I could just figure this out and my no heat issue it would be good. Or at least figure out one of them. Every time I take it to a mechanic to check out they don't find anything and I've been to different mechanics. If I could find someone to take a look on the east coast (Philly, NJ, DE area) that would be great.

The no heat is more than likely your heater core. What symptoms are you experiencing parasitic draw wise? Have you tested your battery and alternator?


Sent from my iPhone using Tapatalk

[firstuser]

The no heat is more than likely your heater core. What symptoms are you experiencing parasitic draw wise? Have you tested your battery and alternator?


Sent from my iPhone using Tapatalk

Thanks Darepoole, the battery I had replaced twice (this drain issue has been going on for about 1.5 years). The alternator I was told is fine. If I drive the car everyday I have no issue at all, no battery drain. If I don't drive it anywhere from 3-5 days I come out to start the car and it won't start. I can jump the car and it runs fine after that. If I pull the fuses 24 (CCM), 38 (CCM), and 39 (Radio) and leave it sit for 3-5 days I have no issue, no battery drain. I havent been able to figure out which one as I'm staring at my DMM right now next to my computer. I was suspecting it might be the CCM under the driver's seat but I'm guessing. Thanks,

[Darepoole]

Thanks Darepoole, the battery I had replaced twice (this drain issue has been going on for about 1.5 years). The alternator I was told is fine. If I drive the car everyday I have no issue at all, no battery drain. If I don't drive it anywhere from 3-5 days I come out to start the car and it won't start. I can jump the car and it runs fine after that. If I pull the fuses 24 (CCM), 38 (CCM), and 39 (Radio) and leave it sit for 3-5 days I have no issue, no battery drain. I havent been able to figure out which one as I'm staring at my DMM right now next to my computer. I was suspecting it might be the CCM under the driver's seat but I'm guessing. Thanks,

Of course! This will sound silly but make sure the battery terminals are secured snug. Likely not the issue but I always throw it out there. I’ve seen mystery battery issues end up being battery terminals just not being tight enough. Has the alternator been replaced ever? Do you have to pull all 3 fuses in order for no drain to occur? I guess you could narrow down the problem area by only pulling one and seeing which is the cause of the draw. Do you have any aftermarket accessories like amps etc?


Sent from my iPhone using Tapatalk

[firstuser]

Thanks, thats a good point about the battery terminals I will check that. I read on another thread someone having that issue and with the battery cable. It is odd how the issue went away and then just came back. I haven't tried doing one fuse at a time but will try that. What made me decide to pull those particular three fuses is from what I read through the threads to be a likely issue so I started there. No aftermarket accessories completley stock. I did replace the radio several years ago with the exact model radio (factory audi radio that came with the car) but the issue started years after that. The reason I replaced the radio was cosmetic, the original radio over the years started getting the peeling buttons. I still have that radio and could swap that back in. As far as the alternator I can't remember if I ever had that replaced, I'm thinking I did but it was a very long time ago if I did. Thanks!

[Darepoole]

Thanks, thats a good point about the battery terminals I will check that. I read on another thread someone having that issue and with the battery cable. It is odd how the issue went away and then just came back. I haven't tried doing one fuse at a time but will try that. What made me decide to pull those particular three fuses is from what I read through the threads to be a likely issue so I started there. No aftermarket accessories completley stock. I did replace the radio several years ago with the exact model radio (factory audi radio that came with the car) but the issue started years after that. The reason I replaced the radio was cosmetic, the original radio over the years started getting the peeling buttons. I still have that radio and could swap that back in. As far as the alternator I can't remember if I ever had that replaced, I'm thinking I did but it was a very long time ago if I did. Thanks!

I gotcha makes sense. That’s a good find with the fuses. You could start but just pulling the radio fuses then that would leave you with the ccm fuses. For sure check battery terminals first though good luck and keep me posted.


Sent from my iPhone using Tapatalk

[firstuser]

I gotcha makes sense. That’s a good find with the fuses. You could start but just pulling the radio fuses then that would leave you with the ccm fuses. For sure check battery terminals first though good luck and keep me posted.


Sent from my iPhone using Tapatalk

Thanks Darepoole,

I will keep you posted, I'll give it a try this weekend. Thanks!

[Halvis]

Are you absolutely sure that the drainage comes from those fuses? or were you just lucky that it did not happen when the fuses were gone? since you said that it has not happened in a few weeks, 3-5 days feels a little too short a time to state that the drainage comes from the fuses


Sent from my iPhone using Audizine Forum

[Turbo510]

Battery posts are not going to be the issue. I've read of issues with the audio amplifier causing battery drain. Also, check that there are no lights on (trunk, glove box, etc.). I understand that you are considering that it's time to part with it. And heck, 367K miles is a good long run. Mine's at 265K and while not as sophisticated as my A5, still does everything I need a car to do so I'm hanging onto it for the time being.

[Darepoole]

Battery posts are not going to be the issue. I've read of issues with the audio amplifier causing battery drain. Also, check that there are no lights on (trunk, glove box, etc.). I understand that you are considering that it's time to part with it. And heck, 367K miles is a good long run. Mine's at 265K and while not as sophisticated as my A5, still does everything I need a car to do so I'm hanging onto it for the time being.

It’s probably not the battery posts but you can’t eliminate it without checking first.


Sent from my iPhone using Tapatalk

[firstuser]

Are you absolutely sure that the drainage comes from those fuses? or were you just lucky that it did not happen when the fuses were gone? since you said that it has not happened in a few weeks, 3-5 days feels a little too short a time to state that the drainage comes from the fuses


Sent from my iPhone using Audizine Forum

Hi Halvis,

Thanks, I thought I was sure. So I would keep the fuses out for weeks and my battery wouldn't drain, everything was fine. Put the fuses in 3-5 days later the battery would drain. I could repeat this over and over. However the last mechanic I took it to hooked up a DMM had the car for a few days and could not find anything ( I had it to three mechanics who said it looked good, nothing wrong) so he put the fuses back in, new ones he said (one looks new CCM-38 the other two aren't, not that it matters). After I got the car back from the mechanic I left the fuses in and no dead battery until a few weeks later when the battery had gone dead. When this happened we had a snow storm the snow melted I could start it and then the next week the car battery was dead. I now have the fuses out after I jumped it yesterday and will see if it goes dead. I just got in testing with my DMM, can someone explaining to me like I'm a 5 year old if I'm using this right? (I should post under questions you are afraid to ask :-). First time I used this for this issue and I've been waching you tube videos and reading instructions and want to make sure I'm not doing this wrong all along and I have the right settings on the DMM.. I have a AstroAI DT132A (if I need a different one I will buy)I plug the black probe wire into COMM and red probe into input. I put the setting on V (I also tried HzV). with the fuses out I put the black and red probe where the fuse would be inside on each side where the fuse would slide in. Then I put the fuses in and like Turbo said above I open the driver's door and manually flip the latch in the closed position. When I did this I felt the click and if I shut the door it would hit the metal (I didn't shut). What I did notice when I did this is the drivers light that is on the door (the part that closes) stayed on (which I believe it shouldn't?) Maybe its not getting a signal to shut that light off with a closed door? I'm going to do this again to make sure I'm not going completely crazy to confirm the light stays on. As far as the readings at first the readings were all over the place while I had the probes on, 20s to .2 so I think I was doing something wrong. But then with the fuses in and fuses out I didn't get a reading above .6. It was a windy out so going to try this again a little later. Thanks!

[firstuser]

Thanks Turbo! I will check the lights. How do I check with the key out? to make sure they are not staying on when they should be off? 265k is alot of miles thats great. I like that our cars aren't as sophisticated as the newer cars. It makes me feel like I am driving an actual car although the new RS3 I am dreaming about all the time. I agree I'm holding onto my car as well although I had seriously considered getting rid of it but I decided not to. This battery drain is annoying me to much I want to figure it out so I'm not getting rid of it. It's not my daily driver anymore and if I was good with cars like you and everyone on here I could just fix these things myself, I'm trying to learn. I'm a computer geek and haven't learned any of this yet. Thanks!

- - - Updated - - -

It’s probably not the battery posts but you can’t eliminate it without checking first.


Sent from my iPhone using Tapatalk

Hi Darepoole,

To check the battery posts do I just make sure the connections are good and tightened? Thanks!

[Darepoole]

Yes just take a 10mm wrench and make sure they are snug on the battery

[firstuser]

Yes just take a 10mm wrench and make sure they are snug on the battery

Great thank you!

[Turbo510]

Thanks Turbo! I will check the lights. How do I check with the key out? to make sure they are not staying on when they should be off?

The trunk and glove box lights are always ready to go without the key. For the trunk, lower one of the rear seats, so you can see if a light is on at night when it's locked.

[firstuser]

The trunk and glove box lights are always ready to go without the key. For the trunk, lower one of the rear seats, so you can see if a light is on at night when it's locked.

went over the fuses again they all seemed fine. i did find a couple things. i start the car put in drive open drivers door shows open on dash. do same thing with rear drivers door shows open on dash. then do same for passenger and passenger rear and neither show open on dash.a few months ago one day I opened the passenger front door and when I tried shutting it I discovered the locking mechanism in the door was broke, it was like closing against metal. I was able to flip it up and shut the door but it kept doing it whenever I shut the passenger door. The car isn't my daily driver and its sits for periods of time and when I do drive it normally noone is with me so that passenger door was probably shut for a couple years (at least a year) when I opened it. I took it to get fixed and they told me it just needed an adjustment in the door and didn't need any new parts and didn't charge me. I should of paid better attention when I got the car back I normally do but when I was just out troubleshooting the front passenger door shut but it doesn't sit flush with the rear door almost like its not closed entirely although the alarm set etc. So maybe this is all related. The issue started way before I took it to the mechanic for that door but the issue with the passenger doors not showing open could have been going on for some time. I checked the trunk lights, going to check tonight because with seats down I can't see any on. I also have both CCM fuses out and have the radio fuse in so I can eliminate the radio as an issue, will see. I checked the boot in the drivers door pulled it back and checked the wires and suprisingly they looked brand new. the battery terminals/cables look good, I wouldn't of been surprised if they didnt look good since I was the last one to replace the battery :-) thanks for everyones help!

[Darepoole]

went over the fuses again they all seemed fine. i did find a couple things. i start the car put in drive open drivers door shows open on dash. do same thing with rear drivers door shows open on dash. then do same for passenger and passenger rear and neither show open on dash.a few months ago one day I opened the passenger front door and when I tried shutting it I discovered the locking mechanism in the door was broke, it was like closing against metal. I was able to flip it up and shut the door but it kept doing it whenever I shut the passenger door. The car isn't my daily driver and its sits for periods of time and when I do drive it normally noone is with me so that passenger door was probably shut for a couple years (at least a year) when I opened it. I took it to get fixed and they told me it just needed an adjustment in the door and didn't need any new parts and didn't charge me. I should of paid better attention when I got the car back I normally do but when I was just out troubleshooting the front passenger door shut but it doesn't sit flush with the rear door almost like its not closed entirely although the alarm set etc. So maybe this is all related. The issue started way before I took it to the mechanic for that door but the issue with the passenger doors not showing open could have been going on for some time. I checked the trunk lights, going to check tonight because with seats down I can't see any on. I also have both CCM fuses out and have the radio fuse in so I can eliminate the radio as an issue, will see. I checked the boot in the drivers door pulled it back and checked the wires and suprisingly they looked brand new. the battery terminals/cables look good, I wouldn't of been surprised if they didnt look good since I was the last one to replace the battery :-) thanks for everyones help!

Does the cluster show the door as open?


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

[firstuser]

Does the cluster show the door as open?


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

oddly it doesn't, it shows all doors closed. And when I open that door(front passenger) it doesn't show as open. same as read passenger doesnt show as open when I open. Thanks!

[Darepoole]

oddly it doesn't, it shows all doors closed. And when I open that door(front passenger) it doesn't show as open. same as read passenger doesnt show as open when I open. Thanks!

If it thinks all the doors are open I’m guessing it would keep all the interior lights off. But this could have something to do with the ccm issues since the doors communicate with it if I’m not mistaken.


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

[firstuser]

If it thinks all the doors are open IÂ’m guessing it would keep all the interior lights off. But this could have something to do with the ccm issues since the doors communicate with it if IÂ’m not mistaken.


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

yeah I would like it better if it thought the doors were open when they werent because that would most likely be the issue but this is the opposite it thinks the passengers doors are closed when they are open. Thanks!

[Darepoole]

yeah I would like it better if it thought the doors were open when they werent because that would most likely be the issue but this is the opposite it thinks the passengers doors are closed when they are open. Thanks!

Yeah seriously it’s unfortunate. Good luck on finding the problem I’m sure it’s frustrating.


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

[firstuser]

Yeah seriously it’s unfortunate. Good luck on finding the problem I’m sure it’s frustrating.


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

thanks for the help! hoping to rule out the radio and then can focus on the CCM maybe and also need to get the passenger side fixed.

[Darepoole]

thanks for the help! hoping to rule out the radio and then can focus on the CCM maybe and also need to get the passenger side fixed.

That sounds like a good plan! I’m interested to see what you find


—————————————————
B5 A4 2.0 Stroker Build (In Progress)

[Halvis]

it feels like your troubleshooting has turned more into guesswork. You should confirm that you really have a drain. I mean… are you sure the alternator works? may not charge the battery properly. Make a current measurement on the battery and make sure you have a drain. I know that it can be a pain in the a$$ at intimate faults.

[firstuser]

it feels like your troubleshooting has turned more into guesswork. You should confirm that you really have a drain. I mean… are you sure the alternator works? may not charge the battery properly. Make a current measurement on the battery and make sure you have a drain. I know that it can be a pain in the a$$ at intimate faults.

Thanks, the drain has been confirmed many times, ccm, radio fuses in battery drains, ccm, radio fuses out no battery drain. That pattern has followed (except once) The alternator is fine, its been checked out but thanks. It's been about 9 days since I tried starting the car, or even opened a door etc, going to let it sit for another week and see if it happens again. The radio fuse is in currently so if it starts I am eliminating that then I will put back in the ccm fuses and see what happens (I suspect its something with the ccm). At this point yes I am partly guessing on what the cause is, I have had it to 3 different mechanics, dealer, and 2 independent (which all found no issue) and I have tested fuses etc and everything has checked out. I'm in the process of getting a vag-com although the mechanics told me they didnt find anything. Thanks,

[EuroxS4]

I can't believe this thread is still going. Could of easily diagnosed this by now with a DVOM.