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Battery Draining? "12v Battery Almost Drained, Switching Infotainment System Off'

01LSi

Passed Driver's Ed
Hi all,

After leaving my car for half a day or overnight I am receiving the following message on my stereo display.
"12v Battery Almost Drained, Switching Infotainment System Off'

However I don't think that the battery is actually draining? I've seen @DV52 post the below warning a couple times. which brings me to my question :
Am I understanding correctly that if you do not ground to earth, then the vehicles systems as a whole might be under the impression that the battery is undercharged even though it is properly charged? At one point I used the CTEK + and - clamps directly to the batteries + and - poles, rather than grounding - to the frame. Could that explain the infotainment system thinking otherwise, and if that's the case how do you retrain the system?

Otherwise - totally plausible - I have another issue that I don't know yet - maybe the battery is dying for example. But when I checked the voltage after allowing it to rest overnight it only went from 12.98v to 12.96v

_________________________________________________

allroads: Need to be real careful when hooking-up any sort of battery charger on a mk7.
Most (all?) mk7s have a battery monitor which sits on the negative terminal of the battery (see pic below), The purpose of the battery monitor (it's part of the power supply LIN bus) is (amongst other roles) to keep a history of the electrical current that is used/inputted) to/from the battery. It provides most of the basic data for the calculation of what VEW calls the System Voltage. System voltage (not battery voltage) is what the control modules use when making decisions related to the vehicle's rail-volts.

Anyhow, it's important when charging a mk7 to INCLUDE the battery monitor in the charging circuit. This means that battery chargers should not be connected directly across the battery (i.e. positive-to-positive and negative-to-negative)

The correct way to charge a mk7 is to hook the positive lead of the charger to the battery positive and the negative lead to a naked engine both (not to the negative battery terminal). If this isn't done the battery monitor is by-passed and the charging current is never recorded!
Don

 

01LSi

Passed Driver's Ed
I did a parasitic draw test with an multimeter and it came up 0 Amps - which a zero reading seems suspicious and I may have to re-do it bc I imagine something under that rating as milliamps should show up? I did the procedure from this video - I pulled the negative clamp off the battery, set the MM to 10A and placed the leads between the clamp and the - battery pole.

Is there a published expected amp draw rating for the mk7.5?
 

01LSi

Passed Driver's Ed
Today I fully charged battery with CTEK charger. Drove 20 minutes. Left it sitting for an hour and got the warning message as mentioned in the title again :/

I have a minidsp that I unplugged prior to this.
I am now unplugging the navtv zenv and seeing if I get that message after driving for another half hour
 

DV52

Drag Racing Champion
Location
Australia
I did a parasitic draw test with an multimeter and it came up 0 Amps - which a zero reading seems suspicious and I may have to re-do it bc I imagine something under that rating as milliamps should show up? I did the procedure from this video - I pulled the negative clamp off the battery, set the MM to 10A and placed the leads between the clamp and the - battery pole.

Is there a published expected amp draw rating for the mk7.5?
01LSI:
Hi all,

After leaving my car for half a day or overnight I am receiving the following message on my stereo display.
"12v Battery Almost Drained, Switching Infotainment System Off'

However I don't think that the battery is actually draining? I've seen @DV52 post the below warning a couple times. which brings me to my question :
Am I understanding correctly that if you do not ground to earth, then the vehicles systems as a whole might be under the impression that the battery is undercharged even though it is properly charged? At one point I used the CTEK + and - clamps directly to the batteries + and - poles, rather than grounding - to the frame. Could that explain the infotainment system thinking otherwise, and if that's the case how do you retrain the system?

Otherwise - totally plausible - I have another issue that I don't know yet - maybe the battery is dying for example. But when I checked the voltage after allowing it to rest overnight it only went from 12.98v to 12.96v

_________________________________________________
01LSI: I suspect your "otherwise" option (i.e. another issue). The nature of the message on the "stereo display" suggests to me that somehow the MIB is sensing a long-term current draw after the car is switched-off. Normally the time that the MIB can remain switched-on without the ignition/engine running is limited by module itself, but I suspect that for some reason this isn't happening in your case.

I'm not sure how you connected the navtv zenv unit - but if you are using an external amplifier - perhaps start there

Don

PS: as for the parasitic draw reading, the most common cause of a zero reading is not setting-up the multi-meter correctly (or a blown fuse inside the multi-meter):
  • Have you selected the correct setting on the dial; it must be set to "amps" and it must be set to DC (not AC)?
  • Have you removed the red multi-meter lead from its normal position and plugged into the socket for amp reading?
 
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01LSi

Passed Driver's Ed
I'm not sure how you connected the navtv zenv unit - but if you are using an external amplifier - perhaps start there

1. Nav TV Zen V
  • Powered by using the same positive and negative wires as the OEM amplifier originally was. I de-pinned the + and - from the OEM amplifier harness underseat. Should it be powered differently you think with a switched accessory instead? I will also double check with NAVTV customer service on their recommendation)
2. MiniDSP 8x12DL DSP
  • Receives remote signal from Nav TV
  • Remote dipswitch setting #2 (won't turn on until it receives voltage signal from NAV TV)
3. Mosconi 5|30 amplifier
  • Receives remote signal from MiniDSP (won't turn on until it receives voltage from MiniDSP)
PS: as for the parasitic draw reading, the most common cause of a zero reading is not setting-up the multi-meter correctly (or a blown fuse inside the multi-meter): .........

I will recheck my process with your notes again next time i plug the system back in piece by piece

Currently I have the entire system disconnected for the next 2 weeks and will see if the warning pops up again. If not I will re connect each component piece by piece
 

kmarriner

Go Kart Newbie
Location
Tempe, AZ
Car(s)
2019 GTI SE DSG
Hi all,

After leaving my car for half a day or overnight I am receiving the following message on my stereo display.
"12v Battery Almost Drained, Switching Infotainment System Off'

Is yours a 2019? Were you able to solve the issue?

My story is that I started getting this error in very early June. When I first got the issue, the dealer replaced my battery under warranty, that did not fix it. I took it back and they replaced the alternator, didn't fix it. Then they replaced the negative battery harness and that fixed it for 5 days, then it came back.
After that they ended up replacing or recoding: The Central Electronics (09) module, Gateway Control Module, Steering Wheel Module, and 5F module. At this point, its been in 5 or 6 times.

Some fixes haven't done anything (IE: Error comes back as soon as I switch off the car after coming home from dealer), some have fixed it halfway (IE: sometimes it works fine, other times I get the error, other time there isn't an error, but KESSY stops working), and some have made it worse (Getting the error as soon as I get in the car before I can even turn it on).

Currently, it works 50% of the time. This issue also causes the interior lights to be shut off when the error pops up and kessy lock/unlock to stop working. It did work error free for 3 days or so this time as well.

I am getting quite frustrated at this point and just want it to work, so any thoughts you have would be helpful. They have escalated my tickets with VW Engineering and the regional rep and shop foreman are both involved.

@DV52, any thoughts?
 

GTIfan99

Autocross Champion
Location
FL
I've been working on a drain issue too, but nothing that bad. I hope you get it solved.
 

kmarriner

Go Kart Newbie
Location
Tempe, AZ
Car(s)
2019 GTI SE DSG
I've been working on a drain issue too, but nothing that bad. I hope you get it solved.

I should add that it's not a drain issue at all. Ever since the alternator replacement I've put my multimeter on the battery several times a week and I've never seen it go below 12.7v. Usually it's 12.8-12.9.
The car just thinks it's low for some reason that no one can figure out, including the engineers.
 

StorableComa

Autocross Champion
Location
SoCal, USA
Car(s)
17 GSW S FWD
Do you have the battery monitoring module, and if so, did they recode the system when they replaced your battery(s)?
 

01LSi

Passed Driver's Ed
I should add that it's not a drain issue at all. Ever since the alternator replacement I've put my multimeter on the battery several times a week and I've never seen it go below 12.7v. Usually it's 12.8-12.9.
The car just thinks it's low for some reason that no one can figure out, including the engineers.

Hey so my suspicion is the same as yours. The car only THINKS that it's losing voltage but it's not true. Car starts up every time no issue. I have the same symptoms as you (kessy stops working, interior LEDs might not light up). As you say, I believe that error is more generic than it leads itself on to be. I don't think that the actual car battery is low because resting voltage / multimeter tests show otherwise and the car always turns on.

Probably the only difference between you and I is I have an aftermarket part installed on the OEM amplifier circuit. I replaced the Fender amplifier with a NAV TV Zen V using the same power harness the Fender amp did. One of the troubleshooting steps I haven't gotten around to yet is that I'm supposed to run power lines directly from the battery instead of the Fender harness and see if bypassing that circuit solves the problem.

But when I unplug the NavTV Zen V the error goes away and everything goes back to normal. Do you have any aftermarket equipment? Even if not, maybe, your stereo system or fender amp is staying on a little too long, or maybe the OEM amp is drawing a little more amperage than the voltage monitoring system is OK with so the system issues that warning and cuts the circuit so your voltage doesn't drop to an actually dangerous level.

So maybe if they replace your amp or recode to default the fender system that will solve the problem? That's my guess at least. But definitely keep me posted I'm curious to know as well and this reminded me that I should try running direct from the battery instead and see how that works for a week.
 

01LSi

Passed Driver's Ed
like ...

if engine is off and >X amps are drawn from stereo circuit cut off the circuit
or
if engine is off and >X volts are drawn from stereo circuit cut off the circuit
or
if engine is off and >X volts are registered at the battery itself cut off the stereo circuit


idk on if it monitors for amperage, but hypothetically, IF the system is monitoring for AMPERAGE draw (sensor indicates X amps are being drawn then cut circuit) then maybe your Fender amp, or my ZEN V, is drawing just a littleeeeeee tiny bit more amps in it's brief on state during accessory mode, that the monitoring threshold for "this many amps is OK" is exceeded and it cuts the circuit.

And / OR in the code somewhere that rating is goofed up too and needs to be reset to tell the system "calm down buddy X is the number amperage draw number you should be worried about"

Could ALSO be based on time criteria too but idk. For example, if system draws X amps over a 1 minute period of time then cut the circuit.
 
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01LSi

Passed Driver's Ed
maybe your fender amp never turns off? I do see my navtv turn off after a minute, at least based on the LED indicator, but maybe that's not within the defined time window / parameters of the cars monitoring system so it cuts the circuit as a safety measure.
 

kmarriner

Go Kart Newbie
Location
Tempe, AZ
Car(s)
2019 GTI SE DSG
Hey so my suspicion is the same as yours. The car only THINKS that it's losing voltage but it's not true. Car starts up every time no issue. I have the same symptoms as you (kessy stops working, interior LEDs might not light up). As you say, I believe that error is more generic than it leads itself on to be. I don't think that the actual car battery is low because resting voltage / multimeter tests show otherwise and the car always turns on.

Probably the only difference between you and I is I have an aftermarket part installed on the OEM amplifier circuit. I replaced the Fender amplifier with a NAV TV Zen V using the same power harness the Fender amp did. One of the troubleshooting steps I haven't gotten around to yet is that I'm supposed to run power lines directly from the battery instead of the Fender harness and see if bypassing that circuit solves the problem.

But when I unplug the NavTV Zen V the error goes away and everything goes back to normal. Do you have any aftermarket equipment? Even if not, maybe, your stereo system or fender amp is staying on a little too long, or maybe the OEM amp is drawing a little more amperage than the voltage monitoring system is OK with so the system issues that warning and cuts the circuit so your voltage doesn't drop to an actually dangerous level.

So maybe if they replace your amp or recode to default the fender system that will solve the problem? That's my guess at least. But definitely keep me posted I'm curious to know as well and this reminded me that I should try running direct from the battery instead and see how that works for a week.

I do have the Fender system, I don't know how I would unplug the amp to test though; unless you mean the sub in the hatch?

The only things I have plugged in are my radar detector and my Cobb AP. But, I used both of those since I bought the car and the error didn't happen for the first 6 months I owned the car, it just happened out of the blue one day. And the error happens when both of those are unhooked from the system.
 

01LSi

Passed Driver's Ed
Well your post inspired me to get off my butt and finally run battery power and chassis ground to the Zen and I still had the error.

You could technically unplug the fender amp just to see what happens. This is total conjecture on my part for you though at this point. I ran amp less for a while with no problem and in my case that worked.

The fender amp is under the driver's seat. Also my rear view camera sometimes stutters and the video "tears", I almost wonder if there is a possible small drain from a pinch in the rear hatch joint 🤷
 
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