hi!

I would like to reduce the brightness of the DRL to extend the life of the LED bulb. From 100% to about 80% brightness. It should glow dimly. How is it possible with VCDS?

You need to change the Dimmwert value in the Leuchte channels that control the DRLs in the BCM.

Daytime / Daylight Running Lights, meant to burn bright, they are for people and drivers to see in Sunlight / times when it is not Headlight / Sidelight time. ie In good visibility. 

 

I would have thought to have this done would cost more than replacement bulbs when they (if indeed they do in the life of the car) blow.

5 hours ago, Mbenyo97 said:

I would like to reduce the brightness of the DRL to extend the life of the LED bulb.

I'd be doubtful that this will extend the life of an LED unit.

1 hour ago, Baxlin said:

I would have thought to have this done would cost more than replacement bulbs when they (if indeed they do in the life of the car) blow.

They're LED strips that are part of the headlamp, so the only way to replace them is buy a new headlamp £££.

 

48 minutes ago, Paws4Thot said:

I'd be doubtful that this will extend the life of an LED unit.

Given that the average lifetime of an LED when illuminated is 50,000 hours i.e. about 5 years 9 months that's an awful lot of driving.

I agree LED lifetime is not extended by reducing their duty cycle as the heat generated is so minimal.

Is there a minimum brightness by law?

22 minutes ago, ords said:

Is there a minimum brightness by law?

Are DRLs required by law?

Just now, Gammyleg said:

Are DRLs required by law?

Yes, on all cars and light good vehicles type approved after 2011.

4 minutes ago, PetrolDave said:

Yes, on all cars and light good vehicles type approved after 2011.

No, that wasn't my question.  OP wants to reduce the brightness, Is there a minimum brightness by law?

38 minutes ago, ords said:

No, that wasn't my question.  OP wants to reduce the brightness, Is there a minimum brightness by law?

But it was the question that @Gammyleg asked 👍

 

I can only find a maximum of 3000 candela, nothing I can easily find about a minimum.

Edited 24 February, 20251 yr by PetrolDave

16 minutes ago, PetrolDave said:

But it was the question that @Gammyleg asked 👍

 

I can only find a maximum of 3000 candela, nothing I can easily find about a minimum.

Ok, I thought he misunderstood my question.