H4 to H7 conversion - DRL's not working

[Adam_T6]

Hello all,

I've fitted H7 to my panel van that left the factory with H4's. Everything works as it should except the DRL's.

Coded BYTE 22, BIT 2 = 0 (low beam forced off while high beam on).
I've tested the bulb - it works.
I've powered the bulb when in the headlight - it works.

The only other thing I've read/can see is BYTE 18 - changing it o '69', but I'm a bit unsure after reading the warning:

 

[Pauly]

There is nothing that needs to be done or coded for this
If the DRLs in a H4 work then they will work in a H7, same wire, same position etc
I would suspect an issue with the headlight itself, the H7 did have an issue with the DRL bulb holders burning out

Personally i would rest the original headlight in the engine bay and connect the H4 headlight back up to prove it one way or the other

 

[Adam_T6]

Thank you for the quick reply.

There isn't a DRL in a H4 headlight is there, only sidelights/main/dipped/indicator?

I've supplied power to the pin for the DRL off vehicle, and the lamp illuminates..

Thanks

 

[Pete C]

Our 2016 T6 with H4 headlights has DRLs. I thought it was a legal requirement ?

Pete

 

[Adam_T6]

It has a separate bulb for a DRL, or it illuminates the '501' sidelight bulb? If it is the sidelight bulb, this doesn't come on unless I turn the sidelights on (no auto headlights).


Cheers

 

[Pauly]

H4 and H7 headlights have DRL lamps in
So now the question is were they working before ?

 

[Adam_T6]

I see, I guess you mean this bulb:


That doesn’t work on the H4 headlights. Maybe I’ve changed a setting in VCDS?

 

[Adam_T6]

BYTE 23, BIT 6 is active:

(I’ve tried removing the handbrake)..

 

[Pauly]

I would start by resetting your coding to original then checking the DRL pin on the headlight connector has 12 volts on it

 

[Adam_T6]

My original scan was on an old laptop, I’ve only got one from a month ago unfortunately - I’ve tried this and no luck.

I’m sure this has got to be coding related, although I’m sure I’ve triedevery possible setting. Maybe I’ll have to get a software update from VW...?

 

[Dieseldonkey]

Are the H7's new or secondhand @Adam_T6 ?

 

[Adam_T6]

Secondhand, but I have tested by powering the headlight connector pins and the bulbs illuminate..

 

[Robert]

Can you quote your original and current BCM coding?

 

[Adam_T6]

Unfortunately I’ve only got coding from a month ago due to a laptop failure - I’ve tried this with no luck.

I had already retrofitted front fogs at this point, I’m sure it’s something to do with them. I did have a play pay night removing them on VCDS, but it didn’t help - the fogs still illuminated for some reason. Although it was getting late... I’ll try again later today.

 

[cgtmiles]

Have it been set to use the fog lights as drls? Isn’t this an option?

 

[Robert]

Unfortunately I’ve only got coding from a month ago due to a laptop failure - I’ve tried this with no luck.

I had already retrofitted front fogs at this point, I’m sure it’s something to do with them. I did have a play pay night removing them on VCDS, but it didn’t help - the fogs still illuminated for some reason. Although it was getting late... I’ll try again later today.

View attachment 70558

Can you change Byte 18 to default hex 69 and report?

 

[Adam_T6]

Thank you all for the help.

Looking at this fresh, I remembered following Petehelmet’s thread about changing BYTE 23, BIT 2 to set fogs as DRL’s.

 

[Adam_T6]

Is there a way of having fogs and headlights DRL’s working?

 

[Robert]

Is there a way of having fogs and headlights DRL’s working?

Together?

 

[Adam_T6]

Yeah both on as DRLs.