Isolating Leisure Battery

[DavidWNE]

I have a 2 year old T6.1 manual that has developed an engine issue (diesel warning light flashes & power drops when accelerating).

I've bought a Carista and to my surprise the only faults are 16777020 - 'function restriction due to service communication interruption'. (9 instances - putting this down to the head unit sometimes cutting out).

263442 - Sirens / alarm horn for anti-theft warning system: No
release by immobilizer (259 instances!). I have a Ghost fitted but can't see it causing this issue?

Neither of these strike me as something that would affect engine power (I was expecting to see DPF/Turbo/injectors or something).

Im nervous to take the van to VW as I fear they will blame the conversion. So before I take it I want to install an isolation to the full campervan electronics and demonstrate that the issue persists.

Question: Ideally I would like to isolate at the positive side of the battery, would this be an issue if I'm only going to use it very infrequently? Is there any benefit in doing this or would adding to the negative be equally as effective?

I have a Redarc DC-DC charger with solar input - would there be an issue if I were to break this circuit using the same isolation (I.e. when the engine was running or sun is shining the charger would have nowhere to go)?

Apologies if these are daft questions as you can tell I'm far from a mechanic, I just want to get things sorted before the warranty runs out in 8 months time!

Thank you,
David

 

[Dellmassive]

You can fit an isolator switch on the main leisure battery POS side,

That will shut off the leisure side,

But as you say the Redarc and solar will still be live.

So you can just disconnect the Redarc feed from the starter battery while testing.

Post a few pics of your starter, leisure battery and the kit, we'll take a look.

 

[roadtripper]

Your feed from the main battery to your leisure system should be fused at either end.

Pull either of those fuses and you've isolated it.

There is no need to isolate grounds.

 

[Dellmassive]

The fault codes are odd. 259 imob ones.....

Radio cutting out, why? Is it stock radio?

How long since last clear of codes?

Maybe log then clear codes and monitor each day for repeat codes.

 

[Dellmassive]

You say it's 2yrs old.

So under warranty.

Id disconnect your camper kit as above and give it to VW for a diagnostic.

The ghost should cause a no start, not a low power issue.......so you could assume the ghost is not a factor.. though I would put the ghost in service mode when giving the Van into the garage.


Also a VW tech one told me that an engine issue with no fault codes is normally due to a mechanical issue.

So what's the mileage and service history.?

EGR been done?

 

[roadtripper]

There is this thread with a link to Ross Tech about the odd immobiliser message

VCDS Fault 17: Instruments -Databus - Missing Message inst

Hi all I have just purchased VCDS (all new to me) and on scanning, I have 2 fault codes I cant shift. any advice or help as to where to start would be great fault 1 Address 09: Cent. Elect. Labels: 5Q0-937-08X-V2.clb Control Module Part Number: 2Q5 937 090 A HW: 2Q5...

www.t6forum.com

 

[DavidWNE]

You say it's 2yrs old.

So under warranty.

Id disconnect your camper kit as above and give it to VW for a diagnostic.

The ghost should cause a no start, not a low power issue.......so you could assume the ghost is not a factor.. though I would put the ghost in service mode when giving the Van into the garage.


Also a VW tech one told me that an engine issue with no fault codes is normally due to a mechanical issue.

So what's the mileage and service history.?

EGR been done?

Thanks for the advice. I will isolate the leisure side and go from there.

I have never cleared the log as I was concerned this may void the warranty? Ideally I would want to reset them all, wait for the diesel engine light to flash on again and run the diagnostic again.

The van has done 14k miles and has had its 2 year warranty service.

The van has had no other work done to it, is there a recall on the EGR?

The Mrs has the van at work but will post some photos if I can dig them out detailing the set up.

Nothing major has been done other than swapping out the factory dc-dc to a redarc and a leisure system ran through a sargent.

Everything has been fitted to a good standard and can't see where any changes I have made could be impacting any of the fault codes / engine.

 

[DavidWNE]

There is this thread with a link to Ross Tech about the odd immobiliser message

VCDS Fault 17: Instruments -Databus - Missing Message inst

Hi all I have just purchased VCDS (all new to me) and on scanning, I have 2 fault codes I cant shift. any advice or help as to where to start would be great fault 1 Address 09: Cent. Elect. Labels: 5Q0-937-08X-V2.clb Control Module Part Number: 2Q5 937 090 A HW: 2Q5...

www.t6forum.com

Thanks for the link. I'll take a look! It doesn't seem to be a very common issue as there's not a great deal online about it

 

[DavidWNE]

The fault codes are odd. 259 imob ones.....

Radio cutting out, why? Is it stock radio?

How long since last clear of codes?

Maybe log then clear codes and monitor each day for repeat codes.

I've noticed it drop out sometimes, when there should be plenty of DAB signal.
Its a fully stock head unit, but I've put the issue down to when the poptop was fitted the installer has removed the stock antenna so it doesn't clash with the poptop, presumably relocated the antenna inside the van and installed a rubber 'bung' where the plastic housing once sat.

Regarding the imob one I will do a test, set the alarm off and see if it sounds and the imob kicks in.

 

[roadtripper]

Nothing major has been done other than swapping out the factory dc-dc to a redarc and a leisure system ran through a sargent.

There isn't a factory dc-dc as such, just a charge relay.

If you've replaced that with the Redarc and used the OEM feed then the main battery fuse in a 6.1 will be the J plate fuse on top of the battery and so not easy to isolate there.

Hopefully the way the Redarc has replaced the charge relay has a more conventional fuse there?

 

[DavidWNE]

I've noticed it drop out sometimes, when there should be plenty of DAB signal.
Its a fully stock head unit, but I've put the issue down to when the poptop was fitted the installer has removed the stock antenna so it doesn't clash with the poptop, presumably relocated the antenna inside the van and installed a rubber 'bung' where the plastic housing once sat.

Regarding the imob one I will do a test, set the alarm off and see if it sounds and the imob kicks in.

 

[roadtripper]

Its a fully stock head unit, but I've put the issue down to when the poptop was fitted the installer has removed the stock antenna so it doesn't clash with the poptop, presumably relocated the antenna inside the van and installed a rubber 'bung' where the plastic housing once sat.

AFAIK the DAB antenna in a 6.1 is in the wing mirror.

(Just checked, DAB/FM/GPS right mirror, FM left mirror according to wiring diagrams)

The shark fin unit on the roof is the 4G/LTE modem and comms for the SOS system et al.

 

[roadtripper]

Is the 4G/LTE connectivity working in your van? You're in the first 3 years so you should have the inclusive We Connect for things like remote monitoring.

 

[DavidWNE]

Is the 4G/LTE connectivity working in your van? You're in the first 3 years so you should have the inclusive We Connect for things like remote monitoring.

Honestly I had no idea this existed. I've downloaded the app and will try and connect it to the van tonight. Cheers for all of the help, very much appreciated.

 

[DavidWNE]

Could I void the warranty by clearing the Carista fault log? Is there any way VW can see that I have done this?

If it is something mechanical the last thing I want to do is give VW an excuse to void the warranty and dip out of stumping up for the cost!

 

[DavidWNE]

Is the 4G/LTE connectivity working in your van? You're in the first 3 years so you should have the inclusive We Connect for things like remote monitoring.

OK so the we connect works fine! Thanks for the heads up.

 

[roadtripper]

Means if your converter moved the 4G/LTE module off the roof it's at least somewhere that it works

 

[DavidWNE]

So I've had a look at the leisure battery wiring and worked out everything camper side is fused thankfully, so no need for additional isolations. Thanks for the advice

 

[roadtripper]

Nice labelling job

That looks like an OE battery top fuse box too, though I'd be itching to add a bus bar or something to tidy up some of the cables.

The only thing I would advise is that you look at moving the connection you have labelled as GPS. That's aligned back over the fuse and nearly touching the unfused battery clamp and that's not good especially with the extreme bend of the cable coming out of the crimp, really needs to turned so the crimp is the other way and much less risk of a short.

 

[DavidWNE]

Nice labelling job

That looks like an OE battery top fuse box too, though I'd be itching to add a bus bar or something to tidy up some of the cables.

The only thing I would advise is that you look at moving the connection you have labelled as GPS. That's aligned back over the fuse and nearly touching the unfused battery clamp and that's not good especially with the extreme bend of the cable coming out of the crimp, really needs to turned so the crimp is the other way and much less risk of a short.

View attachment 213953

Really good shout thank you, will look to reposition that tracker cable.

Agreed I could do with sorting the cables out, a bit of a mess . Might look into a bus bar. Makes sense to me but not so much for someone who didn't install it all!! Cheers