Central Locking / battery discharging

Hi,

First post, hello everyone.

I have a 2001 (to 2005 model)? A4. Central Locking stopped working but would work again after a long drive. This went on for a while until it stopped working altogether over a period of months. If i disconnect the battery it appears to reset the unit and the central locking will work again for a few days then stops working again. Will only come back if i reset the unit. To top this off my car has started running flat if I don't drive it every day now, I've a new battery but still no signigicant improvement. Had a guy look at the central locking(convenience unit) and it was dry. The car when off is draining 9 amps(or ohms or something?) from the battery and when the unit is removed the car is draining 3. It appears to be all connected to this unit but if i replace this is their any guarantee that it isnt something linked to this unit as opposed to the unit itself? Is it a big job to recode the car to a new unit?Electric windows, interior lights etc. all work fine and never had a problem there.

Any ideas anyone? Help would be appreciated.


Edit: sorry, forget to mention I always felt not being able to lock the car caused units to stay alive inside and may have been contributing to the discharge. But I think Ive had it locked a few times and it has still discharged, might have been just after jump starting the car so maybe the battery wouldn't have been suitably recharged. I'm not so sure now, it's been so on/off I'm not sure what days it's done what. I'll leave it locked tonight as the locking will work when i disconnect the battery, reconnect and leave it locked for the night, see what happens.

Quote:

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Originally Posted by tipptopp

Hi,

First post, hello everyone.

I have a 2001 (to 2005 model)? A4. Central Locking stopped working but would work again after a long drive. This went on for a while until it stopped working altogether over a period of months. If i disconnect the battery it appears to reset the unit and the central locking will work again for a few days then stops working again. Will only come back if i reset the unit. To top this off my car has started running flat if I don't drive it every day now, I've a new battery but still no signigicant improvement. Had a guy look at the central locking(convenience unit) and it was dry. The car when off is draining 9 amps(or ohms or something?) from the battery and when the unit is removed the car is draining 3. It appears to be all connected to this unit but if i replace this is their any guarantee that it isnt something linked to this unit as opposed to the unit itself? Is it a big job to recode the car to a new unit?Electric windows, interior lights etc. all work fine and never had a problem there.

Any ideas anyone? Help would be appreciated.


Edit: sorry, forget to mention I always felt not being able to lock the car caused units to stay alive inside and may have been contributing to the discharge. But I think Ive had it locked a few times and it has still discharged, might have been just after jump starting the car so maybe the battery wouldn't have been suitably recharged. I'm not so sure now, it's been so on/off I'm not sure what days it's done what. I'll leave it locked tonight as the locking will work when i disconnect the battery, reconnect and leave it locked for the night, see what happens.

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Hello if it is any help I am trying to locate battery drain on audi 80 Started with 50 m amp. By eliminating radio phone unit got drain down to about 9 m amp. got this reduced to 1.5ma by
disconnecting central locking unit. further reduced by removing
num 4 fuse to 0.5ma. another audi similar has no drain so this is what I am aiming for. I expect 9 ma is excessive drain from
central locking unit. maybe vacum pipes are leaking etc

May be another problem as next test was back to 12.5ma?
by removing 60a fuse at door pillar drop was back to 1.5ma

Hi I had exactly the same symptoms in my Audi, 2001 A4

central locking would work until i locked the car and left it, i had to disconnect the battery to get it working again, if as mine it is the convenience module, i VAG com mine and it has no communication, my work around, for now, is i disconnected the bonnet switch so the alarm doesn't activate as it thinks the bonnet is open, i found this with trial an error and realised when the alarm is activated (ON) the central locking then fails to operate after a few muinits of locking the car.

to test if yours is the same, open the bonnet (doesn't have to be fully up) and lock the car over night or longer than 5 muinites, then if the central locking still works in the morning we know it is the alarm upsetting the convenience module, it really needs a new one but if wish a more permanent solution for free, the bonnet switch can be ditached very easily from the locking mechanism, (it slides left (or right) to ditach) i have left it hangng in the engine bay, the only down side is the bonnet open symbol is constantly on in the dash, but i figure this is easier than disconnecting the battery every morning!!

have a look at my posts (there are not many to look through!!)

The draining battery may be linked but could be many other things not sure how to assist with that one.
My alarm started beeping randomly before the central locking errors which was down to low batterys in the alarm sounder, i disconnected this a while back and thought it may have led to "breaking" my convenience module, Have you had your alarm going off randomly?
I also had a draining battery and thought it could be linked to the low battery in the alarm sounder, after a few checks i thought it was just a coinsidence and i purchased a new battery which is performing fine now.

happy solving,

Andy

Hi follow on from my last post

you also ask:
Is it a big job to recode the car to a new unit?Electric windows, interior lights etc. all work fine and never had a problem there.

I Have priced the convenience module at Audi £200 if you fit it yourself but then you need some one with VAGCOM or buy it also, this is required to place the softcoding onto the module to suit your cars accessories, elec sunroof, elec winsows and so on, I Plan to do it one day but will need help from the guys on this website as to the correct coding values required, it is not diffucult but requres the VAGCOM software, which i have and the codes which i don't have and will need VWaudiforum.co.uk assistance for this. not sure what the fitting cost was from Audi i never asked?

also when your central locking doesn't work check, before resetting, if your interiour light & elec windows work, if like mine they wont work which would point to the convenience module again that is fault, perhaps confincing you that it actually is faulty. once battery disconnected and reset everything as normal!!

I know what you are going through i scratched my head a few times on this one,

let us know what you find out,

regards

Andy