A4 electrics gone wild

[Deek2005]

Hi All

I have an 02 A4 3.0L Quattro Sport with an ongoing electrics problem which is now causing me serious problems.

Last year the passenger electric mirror & window stopped functioning. Garage said I needed a new mirror and window motor. Left it at that as it wasn't really causing too much bother.

Since then the problem seems to be spreading to almost everything in the car. The list of faults is:



Passenger & drivers electric mirrors don't operate
All four electric windows don't operate
When headlights are on dashboard illumination flickers on/off
Central locking button on key fob doesn't lock drivers door
Central locking on/off switch on inside of drivers door doesn't operate
Wipers intermittently go on by themselves
Interior lights intermittently go on by themselves
Indicator lights intermittently go on by themselves
Child safety rear windows on/off switch doesn't operate
Alarm interior cabin sensor activate/deactivate switch doesn't operate
Alarm armed status LED on drivers door flashes when alarm is not armed and car is being driven
Indicator lights don't flash when alarm is activated
Switches on inside of drivers door & rear doors not illuminated

I'm now a little concerned that the alarm isn't actually activating when the car is locked. When the garage said I needed a new mirror & window motor I wasn't convinced that both had died at the same time. Surely this is a centralised fault that is causing things to fail and not everything gradually failing!?!

Any help to point me in the right direction very much appreciated.

Cheers

[benjie]

There's a common problem where drainage points under the battery get clogged and water gets stuck in there and the ECU ends up sitting in a puddle, I expect that would cause a fair few electrical problems, maybe have a look there?

Or get it plugged into VCDS and see what comes up.

[stchris356]

Definatly sounds like water ingress in your BCM, check under your battery for a small pond, if so remove battery and clear drain hole.
Remove BCM which I believe is located inder the passenger footwell, if not correct location I'm sure someone will point this out.

Remove BCM, strip and blow out with compressed air and apply a LOT of electrical contact cleaner and blow dry again, put back together and cross your fingers.
If that does not work you will probably need a new BCM (Body Control Module).

[Deek2005]

Thanks for the pointers. I'll take a look into it and see what I can find.

Cheers

[Kiwi Kranker]

Had a very similar problem in my old A6. Hopefully as described above you can salvage the unit. It is possible...if you are lucky!

Good luck

[Deek2005]

Well...I took the battery out but everything is bone dry. Found two drain holes, took the rubber grommets out and had a look down inside but completely dry and no sign of any gunk/leaves etc. Doesn't look like water has been gathering at any time recently.

Not sure where I go from here, seems to rule out water ingress. :(

[defsix]

Maybe the comfort/conveniance module , lift the carpet and underlay in the passenger front footwell. check for water damage there.

[MCCLATCHIE]

Hi I had alarm and locking problems all was down to the conveniance unit
which is under the carpet front passager side best to unbolt the seat.
The water gets in through or around the pollen filter box.
I found that on my A4 when you pull the plastic lid off this is made tight
the back lip can split so if your car is park on a slop water can slowly drip
through the filter water gets pick up by the foam that is bonded to the back of the carpet and over time gets to the unit and causes problems.
First look at the carpet in the foot well pull it back to see if it is wet.

I repaired mine got a second hand unit from ebay or breakers the only
thing that you will need to do is to recode the door keys can by done
with vagcom.
look at http://www.ross-tech.com/vag-com/download/archives.html

[Deek2005]

I lifted the carpet on the passenger side footwell last night, it seems perfectly dry.

I opened up the protective casing on the convenience module and it doesn't look as if any water has been around.

Maybe simply an electronics failure in the module?

I've also now noticed that the instrument cluster display doesn't show the drivers door as being open when you open the door & the interior light isn't coming on now when the drivers door is opened.

I've been thinking for a while now about getting VCDS so might just do that and see if anything comes up.

[kenney]

Think you need to replace the drivers side door lock,there is a fault with one of the switches

[MCCLATCHIE]

Software can be down loaded on line all you will need is a VAG COM LEAD
Ebay should help lead and usb port softaware.
This con unit controls all electrics .Alarm door lock windows etc.
VAG COM USB DIAGNOSTIC CABLE 409.1 OBD2 II LEAD

[Deek2005]

Think you need to replace the drivers side door lock,there is a fault with one of the switches

Presumably that could upset the central locking, the alarm & most of the alarm/door switches that aren't functioning on the drivers door.

Could be the cause of most of the faults and something unrelated for the rest.

[kite]

Have a look at the loom between the door and the "A" pillar, you could have a broken wire.

[Deek2005]

Bought myself a cable as a stop gap until I get the latest version of VCDS, and have only just started playing with this, but here are the fault codes it's throwing up.

Engine
Control Module Part Number: 8E0 909 559 H
Component and/or Version: 3.0L V6/5V 0001
Software Coding: 0011711
Work Shop Code: WSC 63351

3 Faults Found:
16805 - Warm Up Catalyst: Bank 1: Efficiency Below Threshold
P0421 - 001 - Upper Limit Exceeded
18010 - Power Supply B+ Terminal 30: Voltage too low
P1602 - 002 - Lower Limit Exceeded - Intermittent
16815 - Warm Up Catalyst; Bank 2: Efficiency Below Threshold
P0431 - 001 - Upper Limit Exceeded


ABS Brakes
Control Module Part Number: 8E0 614 517 A
Component and/or Version: ABS/ESP allrad 1726
Software Coding: 04495
Work Shop Code: WSC 06435

1 Fault Found:
01826 - Sensor for Steering Angle (G85): Supply Voltage Terminal 30
35-10 - - - Intermittent


Auto HVAC
Control Module Part Number: 8E0 820 043 B
Component and/or Version: A4 Klimaautomat 1012
Software Coding: 00000
Work Shop Code: WSC 63351

1 Fault Found:
00819 - High Pressure Sensor (G65)
30-00 - Open or Short to B+


Steering Wheel
Control Module Part Number: 8E0 953 549 F
Component and/or Version: Lenksáulenmodul 0308
Software Coding: 00001
Work Shop Code: WSC 63351

2 Faults Found:
01331 - Door Control Module: Driver Side (J386)
49-00 - No Communications
01332 - Door Control Module: Passenger Side (J387)
49-10 - No Communications - Intermittent


Instruments
Control Module Part Number: 8E0 920 950 G
Component and/or Version: KOMBI+WEGFAHRS. RB4 D26
Software Coding: 01400
Work Shop Code: WSC 00844
Additional Info: WAUZZZ8E92A258027 AUZ6Z0B0005148

7 Faults Found:
00457 - Control Module for Network (J519)
49-10 - No Communications - Intermittent
01331 - Door Control Module: Driver Side (J386)
49-00 - No Communications
01332 - Door Control Module: Passenger Side (J387)
49-10 - No Communications - Intermittent
01334 - Door Control Module: Rear Right (J398)
49-10 - No Communications - Intermittent
01333 - Door Control Module; Rear Left (J388)
49-10 - No Communications - Intermittent
00466 - Control Module for Steering Column Electronics (J527)
49-10 - No Communications - Intermittent
01320 - Control Module for Climatronic (J255)
49-10 - No Communications - Intermittent


Seat Memory Driver
Control Module Part Number: 8E0 959 760
Component and/or Version: Sitzmemory R2 F 0203
Software Coding: 00002
Work Shop Code: WSC 00844

3 Faults Found:
01448 - Sensor for Driver Seat: Tilt Adjust (G232)
36-00 - Open Circuit
01331 - Door Control Module: Driver Side (J386)
49-00 - No Communications
01330 - Central Control Module for Central Convenience (J393)
79-00 - Please Check Fault Codes


Central Convenience
Control Module Part Number: 8E0 959 433 AH
Component and/or Version: Komfortgerát T1B 0619
Software Coding: 06859
Work Shop Code: WSC 63351
Additional Info: Steuergerát Fahr. antwortet nicht
Additional Info: 8E2959801 Tõrsteuer.BF BRM 0002
Additional Info: 8E0959801A Tõrsteuer.HL BRM 0002
Additional Info: 8E0959802A Tõrsteuer.HR BRM 0002

6 Faults Found:
01331 - Door Control Module: Driver Side (J386)
49-00 - No Communications
01332 - Door Control Module: Passenger Side (J387)
49-10 - No Communications - Intermittent
01336 - Data Bus For Comfort System
80-10 - Single-Wire Operation - Intermittent
01370 - Alarm triggered by Interior Monitoring
35-00 - -
01332 - Door Control Module: Passenger Side (J387)
80-00 - Single-Wire Operation
01562 - Rear Right Door
61-00 - Won't De-Safe

[kenney]

There is no communication with the drivers door,and an intermittent no communications with the pass door and single wire canbus,which all indicate a wiring problem.Personally i would start by removing the insulation on the wiring to the CCU,remove it as far back as the sill,here you will find a few soldered joints,which corrode and cause various problems.Have you checked the harness between the pillars and the doors?

[paul bish]

damaged wiring to drivers door, check out wiring where it enters drivers door, probably damaged positive wire, causes all off above mentioned problems.

[RON MOODY]

You've got a grand slam list of faults. Before you get in depth, have a good look at the battery earth (ground) to chassis ie unbolt it and clean it up.
As I say so many faults and a high resistance joint on the chassis bonding would be common to all your electrics.

[Screedman]

I may be a bit late here but check for any broken wires between the drivers door and the pillar. The wires are covered with a rubber cover and continually openning and closing the door can lead to broken wires. I am speaking (writing) from personal experience. Look out for a brown wire or more. Very little space to work with though. You have been warned. LOL

[Sfour]

Yeah ill go with that, had a host of electrical faults and after many head scratches 1 broken wire in o/s pillar to door loom and the main power and ground wires insualtion had broken down and where shorting out on each other causing all manner of problems.

loom is about £100 from audi and took me jsut over an hour to fit, windows in effected doors will need to be reprogrammed for fully closed position