Dash Clock Randomly Losing Time After Service

[Skipp]

Hi all,

I’ve run into a strange issue with my 2019 VW T6 after its recent (bi-)annual service, and I’m wondering if anyone here has experienced something similar.

Since the service, the clock has started falling behind - but not in a gradual way. It keeps perfect time for some days, and then suddenly I’ll notice it’s several hours (e.g. 8 hours) behind.

A few details:

The van isn’t driven daily - sometimes it sits for a few days between uses.

I’ve been checking the time without starting the engine (just opening the door to power the dash), and it seemed accurate over several days.

Then suddenly, it’s way off again.

I’ve reset the clock 3–4 times already, but the issue keeps coming back.

Battery was checked during the service and reportedly is in good condition.

Media unit model: 1K8035150H

It feels like the system is intermittently losing stored time rather than drifting.

Has anyone come across this before or have ideas what might be causing it?

 

[Dellmassive]

Try a full battery reset.

Thread '[Guide] Full Van ECU Reset (Capacitive Discharge) -- How I Done It --'

9 Jul 2019

Full Van ECU Reset (Capacitive Discharge) -- How I Done It --

The T6 is full of ECU`s, Modules, CAN Buses and Data packets . . . . . Just like your Phone or PC right.

The motor vehicle industry has spent years with research and development making the modern car/van Data and electrical system very Robust and resilient with built in redundancies and fail-safe measures everywhere.

But, every now and again things can go side-ways and the electrical gremlins come out to play. . . . . . . This is normally caused by electrical situations outside the normal working parameters for the vehicle. ...

• Dellmassive
• bcm ecu fault codes how to guide leisure battery
• Replies: 27
• Forum: Electrics, Lighting, ICE, Security

• 

 

[Skipp]

Thanks for the tip, I will leave it as plan B. I would like to know if anyone has experienced a similar issue and try to understand the reason this is happening.

 

[Phil_j89]

Is the clock set to GPS or manual, in the settings?

 

[Skipp]

I have not been able to find any clock settings available in the media unit (I think the model I have is the most basic one). The only way I have found to adjust the clock is with buttons on the bottom left and bottom right of the instrument cluster - that adjusts the clock shown in the instrument cluster and the media unit. I can separately set the date using overhead engine heater control panel. I have not seen any other clock/date-related settings.

 

[spacewalker]

Is the clock set to GPS or manual, in the settings?

is a T6 mate
T6 - settings from cluster
1K8035150H - thisis basic radio, so how he can get GPS signal from / where / what for ... just antena ? connect to where ?

 

[Skipp]

So, any ideas how/why this is happening? During the annual service dealer inspected battery - still good to go. I checked battery terminals for any lose connections - nothing loose. There is what looks like some sort of aftermarket tracking device (with wi-fi-looking emblem) connected to the battery (the van used to be part of company fleet). I don't know if this could anyhow be related. But the main clue - it all started after the service. Wonder any possible firmware updates during the service could be causing this.

 

[spacewalker]

post vcds autoscan

 

[Skipp]

I don't have vcds

 

[Skipp]

Just to add a bit more context:

I initially thought the issue might be related to the battery slowly losing charge when the van sits unused for a few days, possibly causing the clock to reset. However, the behavior doesn’t quite match that theory.

For example, after resetting the clock without driving, I would expect it to go out of sync again fairly soon if low battery was the cause — but that didn’t happen.

In my latest test cycle:
1. I reset the clock while driving
2. Parked the van and didn’t use it for a few days
3. Checked the time daily — it stayed correct
4. Then suddenly, around day 3–4, the clock was about 8 hours behind

After that, I reset the clock again (without starting the engine), and now - as of today - it’s still showing the correct time.

So it doesn’t seem to be a simple gradual battery drain issue, but rather something intermittent.