[GUIDE] How to retrofit LED projectors to T6 H4 headlights on a VW Transporter

[Robert]

to save a longer wait for getting the autoscan on here ...got the faulty bulb warning light on and wanting it off .. all external lights are ok ( LED )

That is actually a very typical issue.
LEDs consume lower wattage compared with factory fit incandescent bulbs and this causes BCM to "think" that the bulb is faulty.

would any internal lamps cause the warning light ?

No.

 

[catfood12]

That is actually a very typical issue.
LEDs consume lower wattage compared with factory fit incandescent bulbs and this causes BCM to "think" that the bulb is faulty.


No.

How does changing the coding on the BCM improve DAB reception? I though the issue with LEDs was spurious RF from the switching regulator in the LED?

Just curious!

 

[Robert]

The feed produced by the BCM to almost all external lighting can be individually configured as a pure DC or PWMed DC.
PWM in this case is an attempt to improve energy efficiency of incandescent bulbs but with LEDs there are some undesired effects.

Basically PWM signals can generate electromagnetic interference (EMI) and radio frequency interference (RFI) due to the rapid switching and sharp edges of the signal transitions. These high-frequency components can cause unintended electromagnetic emissions and potentially interfere with other nearby electronic devices or communication systems.

 

[catfood12]

The feed produced by the BCM to almost all external lighting can be individually configured as a pure DC or PWMed DC.
PWM in this case is an attempt to improve energy efficiency of incandescent bulbs but with LEDs there are some undesired effects.

Basically PWM signals can generate electromagnetic interference (EMI) and radio frequency interference (RFI) due to the rapid switching and sharp edges of the signal transitions. These high-frequency components can cause unintended electromagnetic emissions and potentially interfere with other nearby electronic devices or communication systems.

Oh, I see. It's a PWM feed to the lamp, not just the PWM output of the regulator inside the lamp.... Where's my VCDS....

 

[Andysmee]

Oh, I see. It's a PWM feed to the lamp, not just the PWM output of the regulator inside the lamp.... Where's my VCDS....

But I didn't find it solved my dab reception issue when the led headlights are on, sorry

 

[catfood12]

But I didn't find it solved my dab reception issue when the led headlights are on, sorry

Well this is what I was seeing from the BCM to the LED driving lamps that I'd changed from incandescent, I thought it was noise back from the LED lamp;



I stuck some chokes in line as below...




Which reduced the line noise to this;



So I thought I'd won, although DAB reception wasn't as good as with the incandescent lamps, so I put them back in and sod the LED vanity.

When I get a moment, I'll try the VCDS tweak as per @Robert .

 

[Der55]

That is actually a very typical issue.
LEDs consume lower wattage compared with factory fit incandescent bulbs and this causes BCM to "think" that the bulb is faulty.


No.

following up with more about this, the bulb warning light went out after my rear reversing camera started working ,
maybe be part of the the same circuit for the lights

 

[Mars2]

Does this coding also work for H7?

I have fitted Osram ZTR H7 LED bulb in my H7 light's. For sure I get light on the dash

Kit de 2 Ampoules H7 LED Osram LEDriving® XTR 6000K - 64210DWXTR

Ampoules LED OSRAM H7 XTR LEDriving, Design Allemand très compact, température de couleur 6000K. Ces H7 LED XTR de remplacement constituent une solution économique et facile d'installation. Vendues par paire.

www.ledperf.com

 

[Mars2]

This coding work great with H7. Thank's

My Van VW T6 TSI 4motion had 8F (10001111) in Byte 16 I switch to DO (1101000). Work great.