Blackice91

Having really strange and aggravating electrical issues with my 2006 A6. While the car is running my interior door lock lights flicker, also I keep getting parking brake malfunction light and tone followed by adaptive light defective light and tone, when these sound my headlights stop working, my wipers stop working, and my power steering stops working. All these come back after about 1-2 seconds but it does it constantly. When not running my alarm will go off immediately so I'm forced to pull the battery cable. The weirdest part is occasionally it will stop and not have any issues but once someone sits in the front passenger seat it starts up again. I pulled the wires from the passenger seat thinking it was that but even totally disconnected it still happens. Now I'm thinking it's just a strange electrical pull that's shorting out the rest of the systems. I bought a VAG but when I run the scan and having these issues it trips so many codes I don't think I'm getting an accurate scan since almost every system codes on the VAG. Any help would be appreciated since this is not only incredibly frustrating but also very dangerous.

Sverige

What scan tool do you have? Normal procedure is to reset (delete) all existing codes then scan again so you note only the current faults. Even if there are many it’s worth posting them up here for discussion, as it should give a clue as to what’s going on.

A6Gary

How old is the battery in your '06 A6? Has it every been replaced? From your description, it would appear that the battery is weak so it is not maintaining the voltage for the electrical systems to function properly.

Blackice91

It's an Autel MST505 VAG for Audi. I did clear them and rescan and still got many codes. I will do it again and write them down and post them. The battery was new when I bought the car 3 years ago. The dealer put it in however it was a used car dealership and it's probably likely they went cheap with it.

Sverige

Battery is definitely a possibility like Gary said. Mine only lasted 4 years and they are known to produce weird symptoms when they’re failing. If, as you say, the previous seller put in an undersized battery it could fail sooner than expected and could dip in voltage when a load is drawn, even if the volts look good while it’s not under load. Have you used a voltmeter across the battery terminals when it’s under some load?

Blackice91

I haven't tried that yet. I will pick one up. I was under the assumption that once the car is running the alternator takes over and the battery no longer provides power to the car, could the alternator have something to do with this as well or does it still draw power from the battery even when running?

Blackice91

I have noticed that the flickering of the inside lock lights intensifies and seems to correlate when I move the seat which is why I thought it was an issue with the passenger seat but maybe that sudden power draw is what's effecting it and not the seat itself. I didn't think about that

Blackice91

That would make sense, I for the life of me couldn't figure out why a short in my seat would cause my power steering, lights, and wipers to all fail. I'm reasonably knowledgeable when it comes to fixing cars but not when it comes to electrical gremlins. I'm sure i could research it but do you know off hand what the proper voltage I'm looking for from my battery?

Sverige

I’m not exactly up to speed myself on these questions, but with a 3 year old battery of uncertain history (could easily have been a second hand one when fitted), my first move would be to put a new one in.

I found this on battery testing
https://www.autobatteries.com/en-us/...ge-and-testing
not audi specific but gives you an idea.

The alternator doesn’t take over supplying power, it provides a charging current to recharge the battery. It is still the battery which powers the car at all times. If the battery is weak and failing, this current from the alternator may not be sufficient, although yes, a faulty alternator could also lead to the same symptoms if the battery isn't getting recharged. Using an external battery charger on the charging posts under the hood (not directly on the batteryterminals!) would help you test how the battery behaves when fully charged.

Blackice91

Ok I bought a voltmeter these are my readings:
Car off on battery 12.08V
Car on on battery 13.54V
Car on charging terminals under hood 14.18V

After clearing codes I'm still faulting these:
05-ACC/ START AUTH
01334 PASSIVE/ SPORADIC
REAR DOOR CONTROL MODULE-J389
NO SIGNAL/ COMMUNICATION
01333 ACTIVE/ STATIC
LEFT REAR DOOR CONTROL MODULE-J388
NO SIGNAL/ COMMUNICATION

36- SEAT MEM. DRVR
01446- ACTIVE/ STATIC
DRIVER SEAT BACKREST ADJUSTMENT SENSOR-G230-NO OR INCORRECT BASIC SETTING/ ADAPTATION
00003- ACTIVE/ STATIC
CONTROL MODULE- NO OR INCORRECT BASIC SETTING/ ADAPTATION

46- CENTRAL CONV.
01134- ACTIVE/ STATIC
ALARM HORN- NO COMMUNICATION

61- BATTERY REGUL.
02276- ACTIVE/ STATIC
STATIC CURRENT STAGE 5-TBD

72- DOOR, REAR RIGHT
02124- ACTIVE/ STATIC
EXTERIOR DOOR HANDLE SWITCH- IMPLAUSIBLE SIGNAL

76- PARK ASSIST
01543- ACTIVE/ STATIC
REAR PARKING AID WARNING BUZZER-H1 5- OPEN CIRCUIT/ SHORT CIRCUIT TO GROUND

78- SLIDE DOOR, RIGHT
02124- ACTIVE/ STATIC
EXTERIOR DOOR HANDLE SWITCH IMPLAUSIBLE SIGNAL