Lighting Madness

[walnuts]

I've been suffering from some really weird problems with my lights, details below, anyone got any idea what the hell is going here? I'll try and keep it short....

So a few weeks ago I noticed that my interior lights had packed up, thanks to the info here I was able to find the relevant fuse and replace it. This revealed that the interior bulb in the rear of the cab (it's a kombi) had blown so I replaced that too. Now all interior lights are working again, so far so good.

However, I then noticed that the DRLs had stopped working completely and the sidelights and dips (H4) were permanently on regardless of switch position. (Yes, they were even on when the switch was in the OFF position!) I checked the bulbs, and I tried disconnecting the battery for an hour to "reset" things. No improvement.

So I take the Van into the VW dealer, that have it all day but can't fix it, they reckon their Technician has spent a couple of hours on it but hasn't got a clue what's wrong. It's now booked to go back in for a couple of days next month for them to have another go.

So this weekend I decide to have another look myself. In the course of this I pulled and checked every single fuse in the dash-box, nothing makes a difference until I pull and replace the fuse that I originally replaced (*) and lo and behold the DRLs start working, and Auto mode starts working (ie. Dips come on and DRLs go off when it's dark). However, now the sidelight are always on, regardless of switch position! Finally I tried disconnecting the battery again, no improvement.

What kind of madness is this!!!!

Anyway, two questions:

1. Does anyone have any suggestions of what else I can try to rectify this? Surely this is just some kind of "computer glitch" and it just needs the right kick up the arse?
2. Can someone confirm in which switch positions the sidelights should be lit. I think I know the answer to this but wonder if now I'm losing my mind.



(* "SC5, Parking lights and glovebox" according to this diagram )

 

[Dellmassive]

What headlights, DRLs, & light switch do you have.... Ie Auto lights Etc..

Couple of pics will help out a lot.

 

[walnuts]

The headlamp units are the bog-standard single headlamp H4 jobs. No LEDS, H4 bulb for dips/heads, W5W for sides, P21W for DRLs.

The switch is this one:

 

[mmi]

2. Can someone confirm in which switch positions the sidelights should be lit. I think I know the answer to this but wonder if now I'm losing my mind.

It depends... if Ignition On, Ignition Off, Key Removed. The latter depends on coding differences (from the factory) based possibly on model year or region (see Vcds Tweaks. )
Anyways, when key is removed from the lock cylinder I have sidelights on only at "1 o'clock" position. That's another story when the key is still in the lock cylinder.

 

[walnuts]

Hmm, I see what you mean.

I haven't tried with ignition off, but with ignition on I get sidelights on in all light-switch positions. That kind be any kind of normal right!?!

Before it all went haywire I'm pretty sure mine was setup as follows (when the ignition was on):

• OFF: DRLs on only
• AUTO: DRLs only (day) / Dips only (night)
• SIDELIGHTS: Sidelights only
• DIPS: Dips only

But it's hard to remember for certain!

 

[Dellmassive]

LEDS here....


But I get this....
when the ignition was on):

But remember on the factory LED units the DRL and side light are the same strip.

• OFF: DRLs on only
• AUTO: DRLs only (day) / Dips & DRL (night)
• SIDELIGHTS: Sidelights/ DRL only
• DIPS: Dips and dim DRL.

Day....



Night....DRLs are on dim.



.

 

[Pauly]

What vehicle is it ?
Is it UK spec ?

 

[walnuts]

It's UK-spec. T32 LWB Highline 2016.

 

[mmi]

So this weekend I decide to have another look myself. In the course of this I pulled and checked every single fuse in the dash-box, nothing makes a difference until I pull and replace the fuse that I originally replaced (*) and lo and behold the DRLs start working, and Auto mode starts working (ie. Dips come on and DRLs go off when it's dark). However, now the sidelight are always on, regardless of switch position! Finally I tried disconnecting the battery again, no improvement.

Read this again and if I read this now right, everything works now - except that sidelights are always on, thus also parking lights at rear are always on. And you would like to have then rather off.

This is exactly how my lights are now (after a coding change) as I wanted to have also sidelights/parking lights always on - even with DRLs. Just wanted to be seen from rear too.

Perhaps the dealer tried to resolve the problem by changing codings and they set and just left/forgot sidelights permanently on (see last lines in my post at Vcds Tweaks. ).

However, the confusing part is what "rectified" the situation when you pulled and replaced the originally replaced fuse... computerized magic?

And, the lights can be coded either the way you think they were, or as @Dellmassive just described. Mine are exactly like you described + sidelights always on. But sidelights could be turned off as mentioned in the link. Also the functionality of switch position SIDELIGHTS can be coded either DRL+sidelights, or just sidelights.

 

[walnuts]

Perhaps the dealer tried to resolve the problem by changing codings and they set and just left/forgot sidelights permanently on (see last lines in my post at Vcds Tweaks. ).

@mmi I think you've probably hit the nail on the head there. I think for now I'm just going put up with it and suggest this to the dealer when it goes back in a few weeks.
Also, your post on that thread suggests it's possible to have the (rear) parking lights on along with the DRLs in daytime but have the sidelights off. Is that right? That would probably be my preferred setup.

At least the DRLs work now, or more to the point all the lights work now (even if not quite the way I would expect).

Cheers.

 

[Dellmassive]

Carista can change those lighting setups.

 

[mmi]

Also, your post on that thread suggests it's possible to have the (rear) parking lights on along with the DRLs in daytime but have the sidelights off. Is that right? That would probably be my preferred setup.

Yes. Basically the first decision is: when ignition is on is either to have parking lights on or off. Then the DRL functionality just comes on top of that. Basic functionality is that DRLs are on at switch positions “0” and “Auto” (in daylight).

At switch position “SIDELIGHT” the DRLs can be coded to be on (as from factory). Or DRLs can be coded to be off – so just plain sidelights.

Verified the above with factory LEDs but should be the same with the other alternatives too.

Quite comprehensive list of available functionality, including lighting functions at VCDS codes list

 

[walnuts]

Carista can change those lighting setups.

Are you sure? I tried Carista this morning. There was an option to toggle DRLs, but nothing for sidelights.

 

[Dellmassive]

Um . . . . . . Ill have to look at the screen shots, i thought i see it in the list . . . .

They are always adding new soft coding.

Carista - How I Done It -

.

 

[mmi]

Are you sure? I tried Carista this morning. There was an option to toggle DRLs, but nothing for sidelights.

Unfortunately not having Carista but I'm under the impression that also Carista can do scans (see Carista) of the modules and thus would expose the codings of the modules. The coding would help us to see if the culprit lies in there.

 

[walnuts]

Here's the scan output from carista.

Nothing specific to lighting.... Perhaps it's in the hex code for "central electronics"?

ECU info obtained with Carista 3.7 for Android:

VIN: retracted

Engine
Part #: 03L906019JP
Coding: 01254012232401080000 (hex)
Component: R4 2.0l TDI
[No fault codes]

Transmission
Part #: 0BT300045T
Coding: 0014 (hex)
Component: DSG DQ500-7F
[No fault codes]

ABS
Part #: 7E0907379P
Coding: 347E4098256984812C76027AA48B21D3390000 (hex)
Component: ESC
[No fault codes]

Instrument cluster
Part #: 7E0920970L
Coding: 470B010100 (hex)
Component: KOMBI
[No fault codes]

Airbags
Part #: 7E0959655D
Coding: 00000000000000000000000000000000304A (hex)
Component: VW10Airbag00J
[No fault codes]

Steering angle
Part #: 6R0959654
Coding: 01 (hex)
Component: LENKW.SENSOR
[No fault codes]

Parking/steering assist
Part #: 7E0919475M
Coding: 108008 (hex)
Component: PARKHILFE 4K
[No fault codes]

Heater & air conditioning
Part #: 7E0907047S
Coding: 0000000003 (hex)
Component: Climatic-T5
[No fault codes]

Central electronics
Part #: 7E0937090
Coding: A0F4793A0A61349193284F746DEB8EF48FA0710F60CC6D60320400230800 (hex)
Component: BCM PQ25 Max4
Fault codes:
03444 Contact-Switch Ignition

CAN network gateway
Part #: 7E0909901
Coding: 042305 (hex)
Component: GW-K-CAN TP20
[No fault codes]

Immobilizer
Part #: 5K0953234
Coding: 000000 (hex)
Component: IMMO
[No fault codes]

Battery regulator
Part #: 7E0907534
Coding: 030B1A73 (hex)
Component: Batt.regelung
[No fault codes]

Infotainment system
Part #: 1K8035150E
Coding: 065700003C00000041111101008000001F0000860000010001 (hex)
Component: MU-E-D-ER
[No fault codes]

 

[mmi]

Here's the scan output from carista.

Nothing specific to lighting.... Perhaps it's in the hex code for "central electronics"?

Yes. The answer is in the module 09-central electronics.
Below the coding just grouped somewhat for readability:


So the specific coding extracted from the hex code in byte 12 tells that parking lights are coded to be ON when ignition (=terminal 15) is ON as the lowest/rightmost bit is "ticked" = "1".

 

[walnuts]

Wow, nice work @mmi !

So when I'm back at the dealer next month I'll basically be telling the technician what to do - "Mate, just set Module 9 Byte 12 to 01101100 will you" - I'm sure he'll love that

It's interesting that this data can be pulled with nothing more than a £2.50 ODB2 dongle, more interesting still that Carista can then modify the codes.
Presumably it would be technically possible to have an App that could allow codes to be modified manually, though it would be pretty dangerous too of course.

 

[andys]

Wow, nice work @mmi !

So when I'm back at the dealer next month I'll basically be telling the technician what to do - "Mate, just set Module 9 Byte 12 to 01101100 will you" - I'm sure he'll love that

It's interesting that this data can be pulled with nothing more than a £2.50 ODB2 dongle, more interesting still that Carista can then modify the codes.
Presumably it would be technically possible to have an App that could allow codes to be modified manually, though it would be pretty dangerous too of course.

You can do this with VCDS. It's only dangerous if you don't take a backup first. I have backups of every different setup I've ever had, along with notes of what I changed and why.

 

[walnuts]

You can do this with VCDS.

Indeed, it's a bit more expensive though!