Just wondering if anyone knows whether the coding to increase the headlight / foglight voltage as per the thread below works , or is even necessary on the Kodiaq??  ie does that kodiaq run a relatively low voltage for the lights to prologue bulb life like other VAG cars?

 

 

9 hours ago, skomaz said:

coding to increase the headlight / foglight voltage

I can't see how that even can work, short of running the alternator every time you switch on main and/or auxiliary headlights.

I don't have any wiring diagrams for Kodiaq, but I wouldn't be surprised if most of the lighting was powered by solid-state stuff, in which case it may well be configurable/controllable as suggested in that link.

Where is the extra voltage coming from? I can see solid state controllers over-running the current, and hence wattage, of a bulb. Still, taking the 127% of nominal wattage, I would guess that you'll shorten the bulb life by 1.6x, so it will only last 60% of the original life time.

If you have a PWM power supply to the bulb, the mean voltage seen by the bulb can be varied between 0 and 100% of the incoming supply. What's being suggested is that the factory default setting isn't 100%.

 

'Value' 100 (or 127) as shown in that other thread does not necessarily mean percentage of system voltage, except perhaps if you interpret it as 'percentage of factory default setting'.

Edited 4 August, 20214 yr by Wino

I think it's down to how computers store numbers

 

A value of 127 is 100% and a value of 100 is ~79%.

 

That being said, it's been suggested that the brightness will depend on both the type of light set and the brightness number. Namely that with:

- halogen lights there is no difference between the 100 and 127 settings

- LED lights there is a difference between the 100 and 127 settings

 

Until someone gets a scope to check the PWM duty cycle it's hard to confirm this and it may also be dependant on the LED driver.

 

I was hoping to find a graph online of lumen output vs PWM duty cycle for a halogen bulb but my google-foo has failed me

4 minutes ago, langers2k said:

Until someone gets a scope to check the PWM duty cycle it's hard to confirm this

I would have thought the voltage (as measured with a multimeter) at the bulb would be adequate to see if anything changes?

 

It'll depend on the multi-meter and the frequency of the PWM

 

Some will probably be close enough, others might not be and some may confused if there is any back EMF from inductors etc in LED drivers 

For info I was asking to see whether it would be a worthwhile change.

 

I have an SE with halogen lights and, coming from an Octy II with HID and a Swift with LED lights, was debating changing the Kodiaq bulbs to higher output Halogen ones as and when I get the chance as winter approaches but thought I'd ask about the coding change to see if that was worthwhile as well given it's the same platform.

 

At present, whilst I have a couple of multimeters I don't have VCDS or OBDeleven (and don't have much  clue about coding...) so can't trial this and haven't seen any evidence or otherwise that it works on a Kodiaq as most owners have higher spec LED equipped vehicles than my lowly SE...

 

Would be good to know either way as I'm certainly not keen on putting LED's in the standard reflectors and, from what I can make out retrofitting OE LED light units will be expensive and awkward.

 

 

@langers2k I wasn't considering trying to measure anything with LED lighting, just the halogen set up that Skomaz has. 

Is there someone nearby with VCDS maybe?

 

Thinking about it, it might be interesting to measure it even without having any way of trying to change it, to see how it does compare to the voltages reported in that other thread.

Things may get very confusing though, as the system voltage in recent cars must fluctuate around a lot with the variation in alternator voltage setpoint due to the micro hybrid malarkey.  I wonder if the PWMs of systems get dynamically tuned to compensate for these effects?

 

Edited 4 August, 20214 yr by Wino

On 04/08/2021 at 11:03, Wino said:

@langers2k I wasn't considering trying to measure anything with LED lighting, just the halogen set up that Skomaz has. 

 

Thinking about it, it might be interesting to measure it even without having any way of trying to change it, to see how it does compare to the voltages reported in that other thread.

Things may get very confusing though, as the system voltage in recent cars must fluctuate around a lot with the variation in alternator voltage setpoint due to the micro hybrid malarkey.  I wonder if the PWMs of systems get dynamically tuned to compensate for these effects?

 

 

 

Right I finally got round to this today as I decided to chuck some Osram Nightbreaker +150's in the dipped and main beam headlights.

 

• Engine off, OE Osram H7 bulb in and lit I got 11.4v across the bulb terminals with my digital mulitmeter
• Same as above but with engine on I got 12.78 across the bulb terminals with a very slight fluctuation over time (maybe 0.03v)

 

So not massively conclusive but does seem to indicate that the voltage isn't throttled back to the same extent as I expected.

 

Either way the Nightbreakers are in and do seem brighter (hard to tell in daylight) and are definitely a higher kelvin, so will hopefully be an improvement.  I'm slightly annoyed that I bought the +150 just before the +200s came into stock but hey ho.  For info the main beams were an easy fit but the dipped less so as there isn't much room between the back of the headlight unit and the bracket for the gas strut that holds the bonnet up on both sides.  That makes it fiddly to get the bulbs and their clips into the headlight unit if you have man-sized hands and also makes twisting the bayonet fitting of them into the headlight unit itself a bit awkward.  The clips were also quite tight and I ended up having to clean the bulbs with alcohol after getting them into the holders as I think I may just have touched the bulb glass lightly and didn't want to take any chances with them blowing after a short time.

 

Interestingly I also tried to fit some LED W5W bulbs that I got for the Octavia and, whilst they worked fine with no errors they were physically just too long to be able to get them into place.  They go in to the headlight unit through the same opening as the main beam bulb and it's all a bit tight.  So if anyone is looking to change these get bulbs that are a max of 12mm diameter and protrude less than 25mm from the holder.

33 minutes ago, skomaz said:

with engine on I got 12.78 across the bulb terminals

What do you see across battery posts in same conditions (engine running lights on)?

 

2 hours ago, Wino said:

What do you see across battery posts in same conditions (engine running lights on)?

 

 

11.8v engine off

14.5v engine on

 

So the voltage at the bulb connections is ~88% of what could possibly be there if full system voltage were being supplied losslessly. 

I think that does suggest it's being throttled back actively. Can't really imagine 12% being lost otherwise.

So maybe can be de-throttled by suitable coding adjustment.

No it does seem quite a lot to lose.  But 12.8v as standard isn't too bad.  Just wondering if changing coding will make any difference for halogens.

 

I'll see how the nightbreakers are over the next few nights first

1 hour ago, skomaz said:

if changing coding will make any difference for halogens

If you mean whether more voltage will make much difference, I'd say certainly. Brightness goes up with the square of voltage applied, from memory.

But you maybe meant, "if it's an option to adjust"?

4 minutes ago, Wino said:

If you mean whether more voltage will make much difference, I'd say certainly. Brightness goes up with the square of voltage applied, from memory.

But you maybe meant, "if it's an option to adjust"?

 

Both really.  Most of the posts I've tracked down seem to refer to leds rather than halogens...   I guess I need to find someone with vcds locally or stump up for obd11 and work out how to do it myself so I can try it...

So I drove it in the dark tonight and the nightbreakers are an improvement but still not a patch on the Swift's led lights...   So may well be looking to try the coding change to see if the voltage at the bulb can be increased...

 

Edit:  Just had another drive on some less well lit roads and its actually a better result than i first thought, with a much whiter beam and defintely brighter than OE.  Theres still some room for improvement if i can tweak the voltage and they may need lifted a bit to extend the range nit a definite improvement and now pretty much livable with until someone manages to legalise an LED retrofit...

Edited 20 November, 20214 yr by skomaz

Back out again tonight and took the screwdrivers with me.  I adjusted the dipped beam alignment up and, with the Nightbreakers it's made a significant difference.  Interestingly the adjustment screw on the offside light had more effect than the nearside one for the same number of turns but I've adjusted them both the same level difference against a convenient wall on the level and have also checked for glare on a dark road by looking back at the car from 40 yards or so away.  I've had to do this on at least three previous cars with no issues at MOT, or from other road users, so hopefully they'll be OK but will get them double checked as and when I can.

 

I have a sneaky feeling the manufacturers set lights conservatively to start with as my Civic and Mitsubishi were the same when I got them and, with the new bulbs in the Kodiaq the cut off and left kick-up was far more noticeable on darker roads - you could see it on the road surface, and it was clearly short of where it could (should?) be.  It's probably why the Halogens get a particularly bad press compared to the OE LED units but at least now the range is now much more on a par with the Swifts', if not the colour temperature or ultimate brightness.

 

I still intend to have a look at the coding when I get the voltage opportunity though...