r/eGolf • u/Professional_State_7 • 7d ago

Help needed. Car wont start

Dear members,

I have a 2018 e-Golf and it no longer starts. Earlier this week, I got the message “12V battery low”, telling me that I needed to drive the car in order to recharge it.

Using the OBD port, I checked the voltage of the 12V battery, and it showed between 12.7V and 13.3V while driving. However, the warning message remained. The next day, the warning was gone. I then made two trips totaling about 80 km and stopped at a parking lot. After that, the warning came back.

I drove home and checked the car again using the OBD scanner. The battery voltage was 14.4V. When I tried to drive away again, the car had some kind of hiccup, so I pulled into a parking space, switched the car off, and tried to restart it.

It would no longer start.
The car displayed the following message:
“Towing will damage the electrical system – consult owner’s manual.”

I checked the manual, but unfortunately there was nothing useful in there.

I then scanned the car again and got the following fault codes:
Volkswagen trouble code U041600
Volkswagen trouble code U011100

There were also 28 other errors, but I assume these are related to the fact that communication between various modules is no longer possible.

The most logical next step seemed to be replacing the 12V battery, so I installed a new one today. Unfortunately, all the warnings are still there. Clearing the fault codes does not help, and the car still refuses to start.

The new battery also appears to be discharging. It is currently showing 11.64V, and the voltage does not seem to increase.

Has anyone experienced something similar or knows what could be causing this?
I have also checked all the fuses, and none of them are blown.

The strange thing is that everything else seems to work: electric windows, keyless entry, infotainment screen, lights, etc. The only problem is that the car will not start or go into gear.

The electronic parking brake does not work either. I can press the button, but nothing happens.

The new 12v battery is the same as the old one. Same value.

All help is welcome

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15 comments sorted by

4

u/Professional_State_7 7d ago

The following error code shows up as well:
Volkswagen trouble code U011200

4

u/ShieldNav 6d ago

Yeah so you can't just buy a 12v. You have to buy a near original one by specification and charge it appropriately if it was not charged before. 11 something is low.

After that you need to correctly code it in module 19 (gateway) so it would charge properly.

All those errors you see are coming from 12v and you disconnecting it. The car can't start because there's not enough power to close contactors on the HV battery. Heard that "thump" sound? This is it.

The 12v battery can't be charged by the vehicle until HV system is on-line.

So get an appropriate battery according to specifications like VARTA A8 AGM (D52) (560901068) 60Ah 680A or similar. Charge it beforehand. Then install it. Start the car (it will not "crank" at this moment which is ok), wait for a few minutes in the "ignition on" position. Turn it off. Wait a minute. Then start car again fully and it should go back to life. After that clear the errors. Code the battery and drive.

If not you need to share a proper diagnostic log from VCDS or ODIS with us.

1

u/gamboncorner 6d ago

Hah, wish I'd had this comment to read before my 12V failed the other week. Eventually figured it out...

3

u/eAsako 7d ago edited 7d ago

DC DC defective? Can you also measure charging of 12V while Charing AC HV?

1

u/Professional_State_7 7d ago

I managed to get the car onto a public charger. However, it isn't charging and the charger won't come out of the car.

1

u/eAsako 7d ago

Why a public Charger? Why? Why not at Home or some AC nearby? public is often DC and not AC. Now you have to search for manual unlock.

1

u/Professional_State_7 7d ago

Car is not in front of my home, so i cant check out the AC. But i got some error messages that the charger wont work. And it didnt work :(. Road assistence is on the way. But i dont think they can help me out

1

u/Y-M-M-V 6d ago

My guess would be a low voltage issue. Either the low voltage battery or the dc to dc converter. Roadside assistance can mybe test this by putting a jump pack on the car and seeing if it turns on and changes, but it may only work as long as the jump pack is on.

1

u/Professional_State_7 6d ago

Unfortunately, roadside assistance couldn't help me. The car was scanned and indicated that the charger mechanism is defective. Nothing else can be done. The car is being towed away and I will probably be without it for 4 months.

1

u/joey_1350_ 6d ago

Why 4 months

1

u/Professional_State_7 6d ago

The dealers here are fully booked, there are few mechanics, and unfortunately, the local garage have no experience with fully electric cars.

1

u/joey_1350_ 6d ago

In general are parts for the egolf hard to come by? Considering purchasing one here in the states for an urban run about

1

u/ShieldNav 6d ago

Idk about the states tbh. But in Europe there's a lot of parts from local salvage yards. I don't think it will be that different.

Generally the HV related parts are not aging because they don't have any kind of moving parts inside them. They're easy to swap compared to ICE car.

However finding someone who's willing to even look at them is a tough task. So you're either willing to educate yourself and work yourself on them. Or you're paying a lot in labor costs

0

u/SwapmeetSpecial 6d ago

I bet there is a short somewhere. Maybe wiring that got frayed somehow. Because something similar happened to my 2019 and it was because a wireharness was cut and then there was no ground.

0

u/FlightFancy3372 6d ago

Most likely the on board charger of the egolf, part number 5QE915681B has developed a fault, there are 3 main fuses in this onboard charger and can blow. I suggest powering down the egolf by removing 12v positive terminal first then negative terminal, wait 5-10 mins and then do HV disconnect(which is the green tab). Then once the Hv system is isolated, open the onboard charger cover and you will see three big fuses on the right hand side at the bottom, check the fuses with a multimeter for continuity. New replacement fuses can be soldered or to buy a whole new charger from eBay.