Battery Drain

BakPak

BakPak

No Gear
Joined
Dec 30, 2012
Messages
1,527
Reaction score
221
Points
63
Location
Shropshire
Morning everyone, the Audi passed the MOT this morning with no advisories. Happy day!

However I have a problem with something draining the battery. The guy at the MOT garage checked the battery and it is spot on, also the charging aspect is ok.

If I leave the car for a few days, especially in this cold weather, the car will struggle to start if at all. What I tend to do on cold nights is leave it on a trickle charge.

The hazard symbol always remains lit, I have checked it in the mornings before unlocking the car and it is still lit.

I know this can be a needle in a haystack situation but is there any usual suspects to check? Or do any of you clever dudes have a procedure for finding such faults?

Many thanks, Mark.
 
You need to get the car connected to VCDS and see if there are any fault codes recorded. There are many things that can cause the battery to drain like it is.
The hazard switch itself is connected to the onboard supply control unit I believe. When you lock the car the modules should go into a low power sleep mode. If there are issues with the buses that connect the modules or a problem with a module then the car will stop awake.
Quite often these problems are related to damp issues and water leaks.
Getting the car checked for fault codes would be a good start.
 
If you have a meter, set it to "amps" remove the battery earth lead & connect meter between the battery post & earth lead. This will show any currant draw, you could close the bonnet & leave the meter outside, now lock the car & leave for time for everything to close down. You will then see how much currant is being drawn! Do not start the car with meter connected or you will fry the meter!!!
 
I have had this problem with my car since I got it , apart from disconnecting the battery if your going away for a long time , i Just keep a spare set of jump leads in the boot all the time lol
 
Is the CCM under the passenger seat or is it under the carpet in front of the seat? Thanks.
 
The carpet seems determined to not let me pull it up. I've removed door sill trim and glove box, do I have to remove the seat and centre console to get to the CCM out?
 
Yes you have to remove the passenger seat as it makes it so much easier. The ccm is located just in front of the crossmember. Remember the front seats have airbags fitted. I did try without removing the seat but gave up
 
Last edited:
No. I think you could get to it without removing the seat tbh. I just undone the seat mounting bolts and leaned it back,left it connected. Just be careful you don't hit it.lol
 
audi upgrades
Thanks for the heads up mate. Did you just lift the carpet up along the sill?
What a daft place to put a moisture sensitive module.....
 
Just had a look at the seat, hmmm....
Does anyone know the easiest way to remove an electric seat please?
 
I'll have to nip to Halfords in the morning, I haven't got a triple 10.
In case the CCM is kaput there is two b6 Audi at my local scrappy, how do I know if they will be compatible?
 
If you were to change the CCM you would probably have to recode it with VCDS and the CCM works with the remotes for the central locking so you would need to sort out those as well.
Disconnecting the CCM won't lose any of it's config. The CCM is a common fault but isn't always the issue. you really need to get the fault codes read. This will probably give you a good idea where to look rather than just guessing.
Also if you clear any faults there is a good chance you will have resolved the issue.
 
Ordered a fault code reader so I can at least have a look at the fault codes and erase them. I understand these kits have limited use compared to VCDS but for the money worth keeping in the glove box.
 
BakPak said:
Ordered a fault code reader so I can at least have a look at the fault codes and erase them. I understand these kits have limited use compared to VCDS but for the money worth keeping in the glove box.
Click to expand...
hello I had a problem with the battery draing for no apparent reason while being parked and until my neighbour nocked and told me my brake lights were on and would never have found it. Changed the brake light switch and all was fine, I purchased a oem one as there are cheap copies and you must fit them correctly as you only get one chance when stting the brake light switch, the details are on the forum, that was my problem and not yours but it is another avenue to check, cheers from Colin
 
I can't wait to get this reader thing plugged in, however it appears it won't read the codes for the CCM?
 
Try and remove the fuses supplying each module 1 at a time, and see if the hazard switch goes out a few seconds later.
As said, the hazard switch is connected to the power supply control module, but many modules on the bus networks will keep the bus awake.
If its on all the time, try removing the fuse that supplies the door control modules, and see if it then settles and goes out.
If no different put the fuse back, and try another, there are 2 fuses supplying the CCM, one for the power supply control module etc.
As said it is probably damp and moisture somewhere, likely culprits are doors being damp with condensation inside..

After you've stopped and taken the keys out, the hazard light should go out about 30s - 1min later, and stay out till you open a door, lock it etc...

You'll need vcds for in depth digging though...
 
  • Like
Reactions: Arrkon
quiescent drains are the bain of my life at work, attach a meter between the negative terminal and the negative lead, see what its showing, then start pulling fuses (one at a time out/in) and see what difference it makes to the reading of the meter, you should see a drop. As Demus has said, if the hazard switch is staying lit, something is keeping the CAN network alive on the car, and that WILL drain a battery, as the current draw its not far off leaving the ignition on.
 
audi upgrades
Thanks guys I'm waiting for this fault code reader to arrive before touching anything else.
When pulling individual fuses to check for any change in current, do I need to lock the car down as well after removing the particular fuse? I understand the principle behind this pull and check method but how do I put the car into this snooze mode with the controlling fuse removed?
 
I would suggest: turn off the ultrasonics (using the switch in the door pocket), latching the door (using a screwdriver or something to close the catch), then lock it, give it 30 sec then start fault finding.
 
No you don't need to lock it, just take keys out and shut the door, after a while everything will shutdown and the hazard light will go out.
Even if you leave the drivers door open after a while it will all still shut down, the hazard will go out, then about 10 mins later the interior lights will go out as will the door marker lights.
 
Thanks guys, I'm hoping this fault code reader tool turns up tomorrow. I wanted to see what codes it reveals before going any further. I totally understand the method you guys are suggesting, very clever thanks.
I will reveal all tomorrow!
 
Scanner hasn't turned up yet so I had a go with the suggested tests for removing fuses 24 & 38 in turn and the result was the same.
I "shut" the door with a screwdriver shaft and locked the car. As expected the hazard light stayed on until I removed the fuse, I replaced the fuse and unlocked the car. When I locked the car again the light went out for about 3 minutes but came on again and stayed on.
Like I said the results were identical whichever fuse was pulled.
Any other fuse pulling tests?
I have had problems with the car not locking but I don't know which door was causing this. After a couple of presses on the fob I would then get the indicators to flash.
If it fails to lock again I'll walk round and see which door is still unlocked.
Any benefit in taking the door cards off and spraying contact cleaner on anything electronic?
 
If the central convenience module is messing about you'll have to remove both of its fuses to disable it.
Leave its fuses out and just close the door, don't worry about locking it, you don't have to lock it to make it all shut down.
If the hazard switch then goes out and remains off then it probably is the ccm causing it, or something causing the ccm to stay awake..
 
demus said:
If the central convenience module is messing about you'll have to remove both of its fuses to disable it.
Leave its fuses out and just close the door, don't worry about locking it, you don't have to lock it to make it all shut down.
If the hazard switch then goes out and remains off then it probably is the ccm causing it, or something causing the ccm to stay awake..
Click to expand...
you will probably get the tester in the morning failing that it could be Monday, try and wait for it to come before you dif too deep and ruin something else, I feel for you and hope you sort it soon, sorry I could not help cheers from Colin
 
Definatley linked to the ccm then, can you get the car inside for a while, if there is damp somewhere it'll have a chance of drying out, if you can get it in a garage, put it in every night, I've seen this cure strange problems before, damp and condensation can form anywhere and be a real pain in the a''e, particularly in the doors, where you have modules talking to the ccm over the can bus.
Hope you soon get it sorted mate, you can drive without the fuses for the ccm in, but you'll have to manually lock the doors, and electric Windows, mirrors etc won't work, as won't the courtesy lights and reversing lights.. But at least the battery won't drain..
 
I can use the Celica for work next week, I don't mind lol, so tomorrow I'll take all the door cards off and move the passenger seat to get the carpet up.
Even if they are not at fault it sounds like checking for any water ingress isn't a wasted job. I could clean all the connections with contact cleaner too. I know I need to get it properly scanned. I'm hoping this Vgate VS450 will show some useful codes. Incidentally can VCDS be bought as a complete package or do you need a laptop?

The aerial on the Celica was not sealed very well (mounted on the rear quarter) so the inner well was holding a good pint of water!
 
Use the Celica for work indeed, bottom lip out again!!
Won't do no harm to try anyway mate, has this all started since the weather has been cr@p??
 
The weather always finds problems, ******* down or frosty nights. I always try to keep drainage channels clean etc.

I replaced the front door wiring looms recently and I was hoping this would fix the battery drain. The looms were not a perfect match but everything works apart from the electric seat memory panel (no connectors on new loom).

I was thinking of disconnecting each door in turn and then shutting down the car as before. If it then goes into snooze mode I know which door to focus on, assuming it is a door causing the fault. I'll have a look at the CCM first.

Btw the build quality on the Celica is brilliant and I much prefer dealing with Japanese electrical connectors. I removed the whole interior to replace all the speakers and soundproof the car better (not the bonnet though lol).
 
Interesting, if I just close the doors without locking, the light goes out. It only stays on when I lock the doors.
 
BakPak said:
Interesting, if I just close the doors without locking, the light goes out. It only stays on when I lock the doors.
Click to expand...
hooray you are getting somewhere at last at least you have narrowed it down, as for drainage channels when you have time is the one under the battery as this gets clogged up with leaves and you find a load of water swishing around, but that can be done when you are sorted, good on you cheers from Colin
 
Unfortunately not, the light comes back on after a couple of minutes. Just popped the CCM out, everything bone dry. It has been removed before, there was no nuts holding the casing in place.
WP 20160123 15 27 03 Pro
 
audi upgrades
Have you tryied a new battery as your old one might not be holding charge
 
Try pulling the fuse for the door control modules, failing that you could try disconnecting the doors at the pillars.
Give it a few days indoors and when the code reader turns up, clear all the codes that have been set by all the fault finding.
The door open microswitches interestingly don't communicate via the door modules, they are hard wired to the ccm. The locking, Window and mirror control all communicate via canbus to the ccm, so if there is a power failure to the doors the car will still know if they're open or not..
 
I tapped into the loom 2 years ago to have a permanent live for a connector I have in the glove box for gps charging etc.
Have I been naughty doing this? Btw I tapped into headlight switch wire for an ignition live for my after market stereo too!
WP 20160124 13 13 10 Pro
 
You must log in or register to reply here.

Similar threads

P
Battery drain
Replies
17
Views
7K
matt66604
matt66604
I
Battery drain...
Replies
16
Views
1K
AudiLeon
A
T
Battery drain
Replies
6
Views
2K
oldsparkyman
oldsparkyman
A
Battery drain help
Replies
0
Views
1K
Audiavantb6
A
Andyb5tdi
Battery drain/ fuse locations
Replies
6
Views
761
Andyb5tdi
Andyb5tdi
Top
Back