jadedj1

So my kids were playing in the new-to-them car (just picked it up yesterday) and of course they kill the battery. Well after a quick jump, now the sunroof won't open (it worked fine off the lot). I've removed and checked the fuses (passenger side door panel) - I've tried to manually open it (didn't crank it too hard when it didn't really budge) but still nothing. The next step, from what I've read, is to disconnect the battery but I've heard horror stories of what could happen if you do that (to the MMI and such). What do you guys recommend?

J. Patterson

The battery power management shuts down nonessential electronics when the battery is discharged. This in order to provide or preserve power for starting. I’m not sure if it will re-set on its own once you drive some or you’ll need to have the car scanned with VCDS to clear the codes. Of course a dealer can do this too. Sounds likely that you are going to need a battery. Just a heads up that those have to be programmed to the car in order to keep all this working properly. Good luck.

jadedj1

I scanned it and there were no faults. The car has started great since the jump yesterday so I'm not sure I would need a new one. And what needs to be programmed again? Did you mean after a new battery? Who does that?

J. Patterson

jadedj1

Woah, this is way beyond me but I'm sure my local indy guy knows this.

Just to be clear, I don't see why a car with 60K would need a new battery, I just wanted to know if disconnecting it might get the sunroof working again. I'm going to buy some new fuses to see if that does the trick.

dreadlocks

Uh because the original battery would be >6yro by now and they are a consumable component, you could have 10k miles on your car but after 6 years.. it likely needs a new battery..

Pulling out working fuses and putting in working fuses is unlikely too change anything, you can pull the power if you want but you know its under the drivers seat right? I doubt it'll do anything but hey go for it.

Try checking the batteries resting voltage, and the vehicles running voltage.. if they are low, then the car is likely shutting down less critical electronics.. when my battery was dying I could not open the rear hatch, didnt try the sunroof.

yuyueyuyue

Make sure you have a working battery, Then disconnect the negative terminal under driver's seat for a minutes, then make sure the sunroof **** is pointed at 'off' setting, then reconnect the battery.


Then test sunroof. Hold the **** to the max open setting until the sunroof reaches that point. Then close it.


about batteries, my wife's 4 year old Tiguan needed a new battery, it had only 16k on the clock... of course Minnesota winter doesn't help too...

jadedj1

There's no way to test the battery without removing the seat, is there? Is it literally just 4 bolts to remove the seat? The car's been starting fine since the jump yesterday, but the sunroof still doesn't open.

dreadlocks

you can put a multimeter on the jumper posts to check voltage, but if you want to disconnect the battery you gotta pull the seat back.. its just two bolts and then the seat tilts, but the are triple square bolts, not torx or normal bolts so you need the appropriate tools... you need to pull both battery cables off the battery and then short em together for a few seconds to drain any residual energy and then hook em back up.

I ran for a month with a bad battery, started fine every time and never need a jump start once.. but all sorts of crap was acting wonkey or not at all.. MMI was always cold booting and taking forever to load up, rear hatch would not open if car was not running, parking sensors went stupid and keyless entry/start was hit/miss.

I diagnosed it w/a multimeter, resting voltage was like 12v instead of ~12.7v it shoulda been.. running voltage was like ~13v and not ~14.4v it was after a new battery.. my 14 needed a new battery at 50k and 4 years of age.

artunkopar

Car: 2009 A4 B8 Sedan 1.8T

Hi Gang!

Here is my solved sunroof error story. I thought sharing this may help some people and may save your money.

Story:
One day my battery died out and we give it a jump start. Ofcourse ve changed the battery since the battery was too old.

Also, the car gave lots or error codes because of this low battery normally. At this stage there were not any problem at all. (I am explaining this because this may caused to some thinks to go wrong).

One week later, I have just parked out my car in a closed garage and tried to lock and close the tilted up sunroof by using the remote key comfort feature (Worked fine).

After then, when I came back 2 hours later, I realised that the sunroof is not opening and responding to the buttons. And also the comfort key open-close windows and sunroof was not working.

Solving Stage:

1. Checked out the fuses related with the comfort control module and sunroof. ALL OK
2. Check all pins on comfort control module located right rear in the trunk. ALL OK
3. Disassembled and checked the Sunroof buttons. Checked the variable resistor (rotary potentiometer) it is ok and the resistance was 1.6K Ohm in full mode, 160 Ohm in first segment. Checked the buttons functionality with diode continuity mode with the multimeter. All was ok. (In this stage be careful to do not damage the brushes located on the rotary head. it seem i have damaged while checking and show an error later about the button, then I solved it later.)
4. Connected to VCDS cleaned all errors. But some of them remained as below:

__________________________________________________ __________
Friday,11,March,2022,18:33:36:00009
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 20.4.2.0 (x64)
Data version: 20200730 DS317.0
www.Ross-Tech.com





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


Address 46: Central Conv. Labels: 8K0-907-064-46.clb
Control Module Part Number: 8K0 907 064 AL HW: 8K0 907 064 AL
Component and/or Version: BCM2 1.1 H71 0134
Software Coding: 011A0E2000390484033001
Work Shop Code: WSC 06325 123 12345
VCID: 7AFB47EFE5DF50565D-802E
3 Faults Found:

01512 - Control Module for Sliding Roof
005 - No or Incorrect Basic Setting / Adaptation
Freeze Frame:
Fault Status: 01100101
Fault Priority: 2
Fault Frequency: 1
Reset counter: 77
Mileage: 153173 km
Time Indication: 0
Date: 2022.03.11
Time: 18:32:08

01514 - Regulator for Roof
012 - Electrical Fault in Circuit
Freeze Frame:
Fault Status: 01101100
Fault Priority: 2
Fault Frequency: 5
Reset counter: 77
Mileage: 153173 km
Time Indication: 0
Date: 2022.03.11
Time: 18:32:31

03128 - Switch 1 for Sunroof
012 - Electrical Fault in Circuit
Freeze Frame:
Fault Status: 01101100
Fault Priority: 2
Fault Frequency: 4
Reset counter: 77
Mileage: 153173 km
Time Indication: 0
Date: 2022.03.11
Time: 18:32:32
__________________________________________________ ____________

5. So I decided to check the sunroof motor and its control circuit. I have dismount it from the mechanism. All the physical mechanism was ok (cogwheel etc.).
Then I carefully removed the control circuit out of its box. I checked the motor continuity and inner resistance. The motor was also fine since there wasn't any open circuit.
6.Final stage, there was only one possibility that the error should have caused by the PCBA. Be careful here and obey the ESD protection rules to not damage the components. I checked all the sub-components. IC's,Capacitors, relay circuit integrity, mosfet, transistors, resistors everthink was ok. I was freaking out wondering that was wrong at this stage

7. Final decision, Though the circuit board looks clean, I just cleaned the PCB and components' surfaces especially connector pins by using an 80 degree Alcohol Cologne (sanitizer). Ideally some people use different chemical compounds to clean such as Isopropyl alcohol.
Used cotton ear sticks to clean up.

I also should say that I made lots of measurements on all pins. Maybe, I grounded all of them by mistake which may also result to solve the problem. I don't know.

After I plug it back to the car suprisingly everything was perfectly working back again.

If I listen to my mechanic and went to the VW-AUDI service, they would change the whole module probably which is pretty expensive
So don't give up.while looking to find the root cause. Even though a little component would burn up such as an transistor, it would effect everything. These kind of repairs woud cost you 0.5 to 7 USD.

Good luck!