Flat battery issues

Cenick

A2OC Donor
United-Kingdom
Hi All!

I wonder if anyone has come across my problem before, basically the 12v battery is going flat in 2 days, that the original and a new one.

I have the AF cccu and it appears to be ok as far as I can tell.

I could hear a slight ticking sound that appeared to be coming from the engine bay!

Going to be weds before I can take another look and see if I’m able to pinpoint where the actual sound is coming from, hopefully someone may have come across something similar before and have resolved it.

Nothing has been changed recently and no warning lights.


Scan attached, the oil sensor alert is the fuse being removed & I’ve a camshaft sensor on order.


View attachment VU03SKJ.pdf


Thanks


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Is the alarm working correctly? Is it going off? Anything else on the scan? Check the positives and negatives on the battery terminals including the block to the left of the positive terminal. Do think you may have a CCCU issue. Replace the CCCU fuses and check for damp.
 
I have in the past used a digital temp thermo to source a current drain.. make sure the engine is stone cold and then point the digital temp thermo at the electrical components in the engine bay ... if a component is causing a drain it will be making heat .. and will show up. We had this with an alternator that had an internal short but was still showing that it was charging but when left first a few days the short would drain the battery
 
Is the alarm working correctly? Is it going off? Anything else on the scan? Check the positives and negatives on the battery terminals including the block to the left of the positive terminal. Do think you may have a CCCU issue. Replace the CCCU fuses and check for damp.

Thanks for you suggestions.

No that’s the full scan information, the alarm works normally and is isn’t going off randomly.

The battery terminals are all good with no dampness.
Apparently it’s unlikely to be the cccu as it’s the more robust AF type and everything seems to be working normally!

Need to study fuses and perhaps pull one at a time, maybe that will point to the fault eventually?

Cheers


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I have in the past used a digital temp thermo to source a current drain.. make sure the engine is stone cold and then point the digital temp thermo at the electrical components in the engine bay ... if a component is causing a drain it will be making heat .. and will show up. We had this with an alternator that had an internal short but was still showing that it was charging but when left first a few days the short would drain the battery

Maybe an idea... someone else has mentioned an alternator fault on a Polo Tdi with it staying alive after the ignition was off so you maybe onto something.

Thanks


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Firstly connect multimeter to battery to check how much mA car is using. Do not connect the multimeter while car is running because multimeter can burn because of too much amps.
Then you can remove fuses one by one to see if mA reading changes. Or you can remove fuse and connect multimeter instead of it to check mA readings.

 
I had apparently exactly this with two of my cars a few weeks ago - cleaned up the starter earth after a new battery was unable to start the car after a few days parked and it made a hell of a difference - it wasn't that the battery was flat or faulty, just not enough juice in either the new one or the old one (once recharged with the CTEK) with the poor conduction to get the compression needed to start. How many of those faults in your VCDS list could be attributed to the voltage dropping?
 
I had apparently exactly this with two of my cars a few weeks ago - cleaned up the starter earth after a new battery was unable to start the car after a few days parked and it made a hell of a difference - it wasn't that the battery was flat or faulty, just not enough juice in either the new one or the old one (once recharged with the CTEK) with the poor conduction to get the compression needed to start. How many of those faults in your VCDS list could be attributed to the voltage dropping?

On my list to check the earth straps I charged the new battery fully (had it a couple of months in storage) and it fired up immediately on swap over so maybe not the problem of a poor earth but definitely something to check.

Thanks


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On my list to check the earth straps I charged the new battery fully (had it a couple of months in storage) and it fired up immediately on swap over so maybe not the problem of a poor earth but definitely something to check.

Thanks


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Did you clear the codes with vcds, then rescan? As @Robin_Cox says, some errors could well be down to low volts, whether battery or connection issues.
If you haven't, clear them now, and rescan.
Mac.
 
I've just solved the same fault, as has been mentioned, connect a ammeter in series with the batteries negative lead and place it in the bootshelf window where you can see it with the boot closed, let it rest for a couple of minutes, no need to lock, if all good the current drawn will be in the order of 50mA, any more and you have a issue, I had ~180mA.

If you have a issue pull a few fuses at a time, shut doors wait 2 mins to settle and read the current again, doing this I found it was fuse 36 that was causing it all and I traced it to the alarm box in the boot.

If you can work out which fuseway is causing it, you can reconnect in the boot and use the meter in place of the fuse to confirm and then investigate whats off that fuseway.

Good Luck

Regards

Andy
 
I also have a battery drain issue and finally narrowed it down to fuse 2 (radio). It is the original Audi radio cassette so does anyone know how to fix this without replacing the radio. I think my next step will be to remove the radio and see if there are any loose connections, if not I would probably need to buy a new/second hand radio. Anyone else have any other suggestions?
 
Hi Mac, it's a 2002 and Chorus I i think (cassette player)
OK, my next step would be to remove the radio fuse (not sure which, and it's a bit late). The Chorus II has a permanent 12 V supply, (ie: not by the ignition). the radio is switched off and on via the canbus.
The rear amp is also, permanently powered, being switched on by 12V from the radio, and put into standby when that 12V is turned off by the radio. I suspect the drain is either the radio or the rear amp. I may be wrong, of course, but it's a good place to start.
Good luck ?.
Mac.
 
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