'05 A6 C6 4F battery/electrical issues
06-04-2018, 01:45 AM
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'05 A6 C6 4F battery/electrical issues
I've had the car stated in the title for few years now, but lately started experiencing some really weird electrical issues.
The most common issue is that sometimes when driving some of the warning/error lights light up, most common is the ABS and ESP ones. They go away in few minutes usually. Sometimes happens with the oil pressure warning as well. The airbag light is always on, I took the car to a shop and they reset the codes and it went away, but later on it came back. Sometimes there's a full blackout and everything goes off (except engine), the MMI system shuts down, everything on dashboard etc. This usually doesn't go away unless you restart the car (which always doesn't work, I've had to jump start the car few times because of this already)
Today this happened: I started the car and it said that the battery is at about 50% charge. I drove like 20 minutes and the error lights started popping up again. Battery level was at 10%. Was away for 10 minutes and then drove back home. Checked battery charge when I arrived: 100%.
Battery is fine, even tried with a brand new battery but no difference. Something is draining the battery while the car is running, which makes no sense to me. Alternator somehow faulty that it doesn't charge all the time? But it can't be completely dead since most of the time it manages to keep the battery at 100%.
Any ideas?
The most common issue is that sometimes when driving some of the warning/error lights light up, most common is the ABS and ESP ones. They go away in few minutes usually. Sometimes happens with the oil pressure warning as well. The airbag light is always on, I took the car to a shop and they reset the codes and it went away, but later on it came back. Sometimes there's a full blackout and everything goes off (except engine), the MMI system shuts down, everything on dashboard etc. This usually doesn't go away unless you restart the car (which always doesn't work, I've had to jump start the car few times because of this already)
Today this happened: I started the car and it said that the battery is at about 50% charge. I drove like 20 minutes and the error lights started popping up again. Battery level was at 10%. Was away for 10 minutes and then drove back home. Checked battery charge when I arrived: 100%.
Battery is fine, even tried with a brand new battery but no difference. Something is draining the battery while the car is running, which makes no sense to me. Alternator somehow faulty that it doesn't charge all the time? But it can't be completely dead since most of the time it manages to keep the battery at 100%.
Any ideas?
06-09-2018, 12:00 AM
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I have a thingy that shows the battery voltage while engine is running, when the "blackout" happens the voltage shows 8-11v. When the car operates normally, it shows >13v.
What gives? I'm gonna get the alternator checked in few weeks but any other ideas?
What gives? I'm gonna get the alternator checked in few weeks but any other ideas?
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das60 (01-02-2023)
06-09-2018, 09:18 AM
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Because every shop in my area that is specialized in car electronics (since I doubt it's just an alternator issue) is booked full for the next few weeks for some reason. I carry an extra battery in the trunk in case it doesn't want to start so I'm not too worried.
06-09-2018, 12:04 PM
#5
You should not wait to get the alternator looked at.
An extra battery will start the car but it will not help you when you are driving if the alternator is bad. When the car is running electricity come from the alternator and if it is not putting out enough amps it will draw from the battery and will drain it fairly quickly especially if you are using high current draw accessories or even necessities such as a fuel pump or lights.
An extra battery will start the car but it will not help you when you are driving if the alternator is bad. When the car is running electricity come from the alternator and if it is not putting out enough amps it will draw from the battery and will drain it fairly quickly especially if you are using high current draw accessories or even necessities such as a fuel pump or lights.
06-20-2018, 11:06 PM
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So I got the alternator and battery tested and they didn't find anything that was wrong with them.
I cleaned the battery terminals and now it stopped draining the battery randomly, but the error light thingy with ABS/brakes/ESP/parking brake etc. happens, along with the MMI and instrumental cluster shutting down and restarting.
However, after cleaning the terminals the issue above only happens when the car is "cold". When the engine temperature rises to around 90C, it stops doing it. It's not really a problem anymore but pretty annoying that every time you start the car as cold, you have to listen to that beautiful beeping sound for ~5 minutes.
Here's a bad quality video of what actually happens: https://streamable.com/jku4z
I'm really confused about this. Anyone got any ideas?
edit: also in the hidden MMI menu there's few errors: https://i.imgur.com/WMaMm1i.png
I cleaned the battery terminals and now it stopped draining the battery randomly, but the error light thingy with ABS/brakes/ESP/parking brake etc. happens, along with the MMI and instrumental cluster shutting down and restarting.
However, after cleaning the terminals the issue above only happens when the car is "cold". When the engine temperature rises to around 90C, it stops doing it. It's not really a problem anymore but pretty annoying that every time you start the car as cold, you have to listen to that beautiful beeping sound for ~5 minutes.
Here's a bad quality video of what actually happens: https://streamable.com/jku4z
I'm really confused about this. Anyone got any ideas?
edit: also in the hidden MMI menu there's few errors: https://i.imgur.com/WMaMm1i.png
01-24-2020, 05:04 AM
#7
In one of the day, my car showed the same problem, all the signs appeared on the dashboard, it was a miracle in that day the best electricians in alexandria were changing the burned transformer of electricity in my house. One of the guys helped me find the problem, it was on some cables which connect the battery. The next day I changed the cables and the battery and all the signs of the dashboard disappeared. Now I know that the best electricians are good at everything about electrics.
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01-01-2023, 08:02 AM
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I've had the car stated in the title for few years now, but lately started experiencing some really weird electrical issues.
The most common issue is that sometimes when driving some of the warning/error lights light up, most common is the ABS and ESP ones. They go away in few minutes usually. Sometimes happens with the oil pressure warning as well. The airbag light is always on, I took the car to a shop and they reset the codes and it went away, but later on it came back. Sometimes there's a full blackout and everything goes off (except engine), the MMI system shuts down, everything on dashboard etc. This usually doesn't go away unless you restart the car (which always doesn't work, I've had to jump start the car few times because of this already)
Today this happened: I started the car and it said that the battery is at about 50% charge. I drove like 20 minutes and the error lights started popping up again. Battery level was at 10%. Was away for 10 minutes and then drove back home. Checked battery charge when I arrived: 100%.
Battery is fine, even tried with a brand new battery but no difference. Something is draining the battery while the car is running, which makes no sense to me. Alternator somehow faulty that it doesn't charge all the time? But it can't be completely dead since most of the time it manages to keep the battery at 100%.
Any ideas?
The most common issue is that sometimes when driving some of the warning/error lights light up, most common is the ABS and ESP ones. They go away in few minutes usually. Sometimes happens with the oil pressure warning as well. The airbag light is always on, I took the car to a shop and they reset the codes and it went away, but later on it came back. Sometimes there's a full blackout and everything goes off (except engine), the MMI system shuts down, everything on dashboard etc. This usually doesn't go away unless you restart the car (which always doesn't work, I've had to jump start the car few times because of this already)
Today this happened: I started the car and it said that the battery is at about 50% charge. I drove like 20 minutes and the error lights started popping up again. Battery level was at 10%. Was away for 10 minutes and then drove back home. Checked battery charge when I arrived: 100%.
Battery is fine, even tried with a brand new battery but no difference. Something is draining the battery while the car is running, which makes no sense to me. Alternator somehow faulty that it doesn't charge all the time? But it can't be completely dead since most of the time it manages to keep the battery at 100%.
Any ideas?
01-03-2023, 11:13 AM
#9
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The ESP/ABS/Parking Brake issue is your ABS Module. It needs to be replaced or rebuilt. I’ve had two rebuilt now on different A6’s and it fixes the issue perfectly. Google “Audi A6 ABS Module rebuild”. There are a couple of places who can do it for about $250. You pull it, ship it, they rebuild it and send it back in about 5 total days.
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das60 (01-04-2023)
01-11-2023, 04:52 PM
#10
FWIW, I had an issue about a week ago. Thought it was a valet leaving the ignition on. The emergency brake warning was the first symptom. Then the terminal 30 voltages were jumping all over the place. I charged the battery overnight and now change. On a hunch, I pulled the alternator and then the voltage regulator. The brushes were end-of-life. The copper rings were completely covered in carbon. After polishing them, I tested it at Advanced Auto and it was fine.
Rather than buy a $300 Audi voltage regulator, I got a Valeo 595458 and swapped in the brushes following directions on YouTube. Alternator is fine, blizzard of dash lights are gone. Now I just have to see how much damage I did to the battery.
Rather than buy a $300 Audi voltage regulator, I got a Valeo 595458 and swapped in the brushes following directions on YouTube. Alternator is fine, blizzard of dash lights are gone. Now I just have to see how much damage I did to the battery.
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jonzie77 (01-11-2023)