serious battery drain problem b6 01 Help

[rob irl tdi]

My mate has a serious drain on his 130 2001. Its almost 7 volts on the multimeter.Pulled ouy all the fuses and its still there. Pulled out the central convience module and its bone dry still a drain.

We pulled out the central electrics relays and fuses overs the drivers side one at a time and the drain remains on the multimeter at the battery.

It goes from 7 down to 2 and back up again. This seems to happen while the hazard light switch lights up its self on its own.

Disconnected the altenator wires too with no luck.

 

[NHN]

I was about to say disconnect your radio & test, there have been issues like this with radios mate, but then read your hazard switch issues, have you disconnected that to see if it stops draining.

 

[rob irl tdi]

I disconnected the aftermarket radio and the drain was still there. No I never disconnected the switch itself. Could it be? I no the door lock on the drivers side isn't working. The car cannot tell if it its door is opena a nd the alarm buttons in the drivers door won't light up by pressing them

That isn't related to my problem tho.

Is there another relay unit under the Engine ECU?

Just get low voltage readings with VCDS

 

[rob irl tdi]

No sound of relays either with that hazard switch lighting up on its own.

 

[NHN]

Uh it may well be related to your problem if it is intermittantly thinking doors open or shut as this obviously controls the interior lights aswell, turn of the interior roof lights & see if it improves, the lock has microswitches inside, spray it with wd40 to see if it removes some gunk in the lock, if not remove lock & take apart & clean out, if no luck then change lock, also I'd advise a scan with vagcom & maybe some lock measuring block logs if supported on your car age.

Yes remove hazard switch aswell, see if anything makes a difference.

 

[Woorlord]

To isolate the doors completely out of the problem simply unplug the door connectors in the A and B-pillars under the rubber gators.
One relay by the engine ECU (Plenum Chamber) is the immobiliser relay - this energises the starter motor via a feed from the ECU - doubt if this has anything to do with your problem.

Are yoy checking the current drain on the battery by measuring Amps with a suitable meter?
Disconnect one side of the battery and put an Ammeter in line between the battery terminal and the disconnected cable - do not start the car with this meter connected as this will fry your meter unless it is rated at 100Amps or so.
Measuring volts is not the way to find the drain, if the reading is less than 12v then yes it's not right but that's all you can deduce!

As you disconnect items / remove fuses the Amp reading should decrease.
When the car is inactive you should be looking at a figure much less than 1 Amp - I'll try and take an actual reading tonight and post-up.

Another sugestion - Alarm siren in boot - internal backup batteries corrode and destroy the internal circuitry. This could be causing an unnecessary power drain but would be isolated by removing all Convenience Module fuses.

 

[CHRIS555]

Probably totally wrong, but I'll pop this reply incase it helps anyone in the future - I had a B5 with the same problem, it turned out to be the amp on the rear speaker - it basically stayed on and drained the battery over time

 

[quattrojames]

The hazard light switch can fail, see THIS thread.

 

[rob irl tdi]

Oh yea lads I disconnected the door loom at the A pillar. Convience module everything unplugged and still a drain yesterday.

It could be the switch its self

 

[rob irl tdi]

To isolate the doors completely out of the problem simply unplug the door connectors in the A and B-pillars under the rubber gators.
One relay by the engine ECU (Plenum Chamber) is the immobiliser relay - this energises the starter motor via a feed from the ECU - doubt if this has anything to do with your problem.

Are yoy checking the current drain on the battery by measuring Amps with a suitable meter?
Disconnect one side of the battery and put an Ammeter in line between the battery terminal and the disconnected cable - do not start the car with this meter connected as this will fry your meter unless it is rated at 100Amps or so.
Measuring volts is not the way to find the drain, if the reading is less than 12v then yes it's not right but that's all you can deduce!

As you disconnect items / remove fuses the Amp reading should decrease.
When the car is inactive you should be looking at a figure much less than 1 Amp - I'll try and take an actual reading tonight and post-up.

Another sugestion - Alarm siren in boot - internal backup batteries corrode and destroy the internal circuitry. This could be causing an unnecessary power drain but would be isolated by removing all Convenience Module fuses.

Sorry Woorlord, its amps. Our friend is a mechanic and we cannot find the problem. The car belong to our mate.

The door look would not cause the drain even tho its not working the interior light or the symbol on the DIS to let it know the car door is open.

I had these locks go on me in the mk4 golfs ive owned

I'll post a scan of it up.

 

[rob irl tdi]

Here it is lads



VCDS Version: Release 908.0
Data version: 20090911

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

Chassis Type: 8E - Audi A4 B6/B7
Scan: 01 02 03 08 09 0F 11 15 16 17 18 36 37 45 46 55 56 57 65 67
69 75 76 77

VIN: WAUZZZ8E12A062793 Mileage: 193580km/120285miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 038-906-019-AVF.lbl
Part No: 038 906 019 FP
Component: 1,9l R4 EDC 0000SG 1467
Coding: 00002
Shop #: WSC 63351
WAUZZZ8E12A062793 AUZ6Z0A0151900
No fault code found.
Readiness: 0 0 X X X
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8E0-614-517.lbl
Part No: 8E0 614 517
Component: ABS/ESP front 1726
Coding: 04255
Shop #: WSC 00598
2 Faults Found:
01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30
35-00 - -
00778 - Steering Angle Sensor (G85)
37-10 - Faulty - Intermittent
-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043
Component: A4 Klimaautomat 0711
Coding: 00000
Shop #: WSC 63351
No fault code found.
-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 8E0-907-279-8E2.lbl
Part No: 8E0 907 279 B
Component: int. Lastmodul RDW 1512
Coding: 00001
Shop #: WSC 00000
1 Fault Found:
00532 - Supply Voltage B+
53-10 - Supply Voltage Too Low - Intermittent
-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8E0-959-655-84.lbl
Part No: 8E0 959 655
Component: Airbag 8.4E 3001
Coding: 0010602
Shop #: WSC 63351 000 00000
1 Fault Found:
00532 - Supply Voltage B+
002 - Lower Limit Exceeded - Intermittent
-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8E0-953-549.lbl
Part No: 8E0 953 549 F
Component: Lenksáulenmodul 0202
Coding: 00011
Shop #: WSC 63351
No fault code found.
-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8E0-920-9xx-8E2.lbl
Part No: 8E0 920 950 FX
Component: KOMBI+WEGFAHRS. RB4 D28
Coding: 00400
Shop #: WSC 00000
WAUZZZ8E12A062793 AUZ6Z0A0151900
2 Faults Found:
00668 - Supply Voltage Terminal 30
53-10 - Supply Voltage Too Low - Intermittent
01304 - Radio
49-00 - No Communications
-------------------------------------------------------------------------------
Address 45: Inter. Monitor Labels: 8E0-951-177.lbl
Part No: 8E0 951 177
Component: Innenraumueberw. 0504
Coding: 00001
Shop #: WSC 00000
No fault code found.
-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 8E0-959-433-MIN.lbl
Part No: 8E0 959 433 AL
Component: Komfortgerát T9F 0514
Coding: 06859
Shop #: WSC 63351
Part No: 8E2959802B
Component: Tõrsteuer.FS BRM 4.11
Part No: 8E2959801B
Component: Tõrsteuer.BF BRM 4.11
6 Faults Found:
01330 - Central Control Module for Central Convenience (J393)
53-10 - Supply Voltage Too Low - Intermittent
01370 - Alarm triggered by Interior Monitoring
35-00 - -
01561 - Left Rear Door
61-00 - Won't De-Safe
01559 - Drivers Door
61-00 - Won't De-Safe
01331 - Door Control Module; Driver Side (J386)
53-10 - Supply Voltage Too Low - Intermittent
01332 - Door Control Module; Passenger Side (J387)
53-10 - Supply Voltage Too Low - Intermittent
End ---------------------------------------------------------------------

 

[ScottyP45]

supply B+ too low doesnt necessarily indicate a drain or short, rather an intermittent break in the power to the wire or circuit common to the parts that show an error code.

A fuse in the ECU compartment may have blown, or power to the central convenience module (fuse again or relay) may be intermittent in the same way.

 

[defsix]

My mate has a serious drain on his 130 2001. Its almost 7 volts on the multimeter.Pulled ouy all the fuses and its still there. Pulled out the central convience module and its bone dry still a drain.

We pulled out the central electrics relays and fuses overs the drivers side one at a time and the drain remains on the multimeter at the battery.

It goes from 7 down to 2 and back up again. This seems to happen while the hazard light switch lights up its self on its own.

Disconnected the altenator wires too with no luck.

You should be measuring DC Amps not volts. Measuring volts won't tell you anything useful in this circumstance.

 

[rob irl tdi]

supply B+ too low doesnt necessarily indicate a drain or short, rather an intermittent break in the power to the wire or circuit common to the parts that show an error code.

A fuse in the ECU compartment may have blown, or power to the central convenience module (fuse again or relay) may be intermittent in the same way.

Cheers we'll heave a look at the Ecu and relays in there and see tomorrow.

The car did get a new battery before andit drained it in a couple of days

 

[Woorlord]

On from my previous post #6, indicating you should be checking out the current drain in Amps.
As promised, using my Fluke 87 DVM with 10A current range with 100ms recording function, (sounds good anyway), here are some "good" figures for comparison......

All doors closed (not locked), Bonnet up, Hazard switch backlit illumination OFF, I think most systems have shut down and the current values vary as follows:

min=32mA / max=76mA / Average=40mA
​

Open the drivers door (interior light already set to off) and the drain shoots up to 2.871A
Dash board mileage and clock light up, door red warning lights come on, drivers footwell light on, etc.
After shutting the drivers door again, the Hazard switch light stays on for a while then turns off and the current drain drops down to 2.409A
After a short time (minute or so) systems start to shut down and current drain drops gradually and reverts between 32mA and 76mA as stated initially.

Hope this helps?

 

[rob irl tdi]

Thanks Woorlord, but i'm still none the wiser on this car

I've swapped my hazard switch wit mine and it is doing the same.

After locking it the harzard light stays on which is normal and then goes off.

It starts flashing later on and off which it is not nomal
and thats when we get the amp reading up and down on the battery

Forgot to say too the you can hear the doors kinda clicking forsome reason too. Don't know if this is linked to the fact theat we know his drivers door lock switch is fecked

I haven't tried the ECU of whats under it yet but that the last place I have to check if there is a relay of fuse gone.

This car have been with a few mechanics that are puzzeled.

 

[BILKO1]

Have you tried disconnecting the wires going to the alternator? If a diode goes short circuit it can back feed causing a largish drain, the alternator will still show good readings when operating. I've seen this several times on various makes and models and the drain is normally over 4-5 amps.

 

[rob irl tdi]

Yes the alternator was disconnected and still a drain on the multimeter

 

[Woorlord]

Yes the alternator was disconnected and still a drain on the multimeter

It would be good if you could put some meter reading figures to your tests on removing fuses, switches, alternators - you are always going to get a current drain if the battery is connected it's the magnitude and duration that decide how long your battery can provide the relevant power.
Please give us some "A" or "mA" readings.

 

[Tazzie]

Hi
I was just wondering if ever got the bottom of this issue, as my car has the same symptoms!

 

[marktdisport]

i also know someone with the same issue !!!! with the central locking not working now..... on previous threads the alarm siren/battery back up always pops up's have you checked this out

 

[saxonblue]

i had the verry same problem on my old a4,( 2.0se 130)
the hazard lights switch was staying on for ages. the battery was dead within hours, evan a brand new 1 at a cost of £145 from halfords didnt do the trick
2 auto electricains, an audi garage, and a few loacal garages could not sort this thing out, BUT when you say " no the door lock on the drivers side isn't working. The car cannot tell if it its door is opena a nd the alarm buttons in the drivers door won't light up by pressing them

That isn't related to my problem tho."
dont be fooled,, it more than likly is, trust me
i had a 7.5 amp draine on mine, did all the things your talking about and nothing sortid it out, when all the fuses wer put back in, here it is againe was the cry. it droped to just over 2 amps when the (after market) cd/dvd player was taken out, fitted it to another a4 and everything was ok?????? amps looked at and all fine, DOOR LOCKS LOOKED AT AND???????? BINGO, (so thought) disconected and everything was ok, all the lovley amps where back where they belong,,in my (yet another) new battery, but all the locks and windows and blinking led light etc etc were working fine when they were connected, so god know why.. all pluged back in and checked out againe and the amps still droped but only 4 this time,
after A LOT of digging, turns out it was the locks, and a little un known about speeker/mic for a hands free kit hidden right under the dash that was going faulty,
kit taken out stamped on a good few times, and the door locks pizzes through with a good blast of wd40 and,,, they lived happley ever after ,,,the end

 

[rob irl tdi]

It was the central convience unit in the end. It was dry but must have been damaged before