DRL LED Bar brightness boosted using Forscan

[ROBB1]

I think thats worth a shot. I may try this out tomorrow. I have the DRL Lamp Circuit Usage set to Fixed DRL Position. I think its worth seeing what ramping up the duty cycle on the DIM cfg does. If it does work, It honestly seems like the proper way to do it. Listed values below for easy access

DRL_Ckt_FixedDim_DutyCycle_Cfg
726-38-01 xxxx **xx xx--

64 =100%
5A = 90%
4B =75%
32 = 50%
19 = 25%
0A =10%

Definitely report back and hopefully this fixed the flickering issue most people seem to be having. ??

Ok I set the fixed dim duty cycle to 75% this morning. It had the expected effect of increasing the DRL output with the headlights or parking lights on. Even at 75% they are pretty screaming bright. I will run this way for awhile and see if the flicker comes back. If not, I will bump it 90% for testing. Honestly I think 75% is probably more than enough for the desired effect.

726-38-01 xxxx 4Bxx xx--

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[ROBB1]

If this works, I think it confirms we are bumping up against the max output capability of the BCM and the most current sensitive LED string is exhibiting the flicker. That would explain why some of us see it in the headlight string and others in the fog string, but not both even though they are wired to the same BCM output.

If this was a logic based conflict both should flicker (at least that's my theory).

 

[antho]

I went ahead and went to 75% as well. Can tell visually that it worked. Will keep an eye on it as well

 

[Jesse-Infotainment]

Would the flicker happen soon after the change?

 

[antho]

Would the flicker happen soon after the change?

I only noticed mine one night during a long drive. So i disabled it while on the road trip. I dont really have any info on replicating.

 

[ROBB1]

Would the flicker happen soon after the change?

For me it was very intermittent. I could never reproduce it when I wanted it to happen for troubleshooting. I would occasionally see it when I was behind something reflective or a store window. Always while the headlights were on. Never had it happen before or after in DRL only mode.

 

[Nightshade]

[/QUOTE]

Ok I set the fixed dim duty cycle to 75% this morning. It had the expected effect of increasing the DRL output with the headlights or parking lights on. Even at 75% they are pretty screaming bright. I will run this way for awhile and see if the flicker comes back. If not, I will bump it 90% for testing. Honestly I think 75% is probably more than enough for the desired effect.

726-38-01 xxxx 4Bxx xx--

This is great news for those having flickering issues! Great work! I just sent you a PM to get a bit more info.

 

[F150 John]

What is the default amount for the PWM and are you worried about what adjusting the PWM will do for the lifespan of the let's?

There is normally a good reason for the duty cycle of a PWM in how it's setup for driving a circuit and while sometimes you are ok to Makena adjustment to it that can often come at the cost of increased head and shorter lifespan of what is being driven.

If we had the specs of the led they used in the bad you could do the load calculations and compare it to the white sheet and see what is the trade off but in this case it's a shot in the dark.

 

[Jesse-Infotainment]

What is the default amount for the PWM and are you worried about what adjusting the PWM will do for the lifespan of the let's?

There is normally a good reason for the duty cycle of a PWM in how it's setup for driving a circuit and while sometimes you are ok to Makena adjustment to it that can often come at the cost of increased head and shorter lifespan of what is being driven.

If we had the specs of the led they used in the bad you could do the load calculations and compare it to the white sheet and see what is the trade off but in this case it's a shot in the dark.

How? The duty cycle is 100% so why would changing the dim duty cycle be detrimental?

 

[F150 John]

So are you saying stock the cycle time is normally at 100% and decreasing it make it both brighter and yet removes the flicker?

I have not looked at the output to see what the stock output is doing as far as cycle time nor have I seen the stock setting where it was before any changes. If I was off base my bad. Just don't understand why a decrease in cycle time would increase the brightness.

 

[F150 John]

I think I misread a post. I decrease of duty cycle should have the effect of less light output. I also don't know why it would help with the flicker sense it should make it at least on paper flicker more but if the output was being dragged down then a decrease of duty cycle would help with flicker at that point.

My bad on misreading the post and taking it that it somehow implied that it kicked up the brightness when the post was referring to it was still bright.

 

[antho]

That is what I am wondering as well. If changing the line for the LED brightness then changing the cycle time, which is both at 100% maxed out brightness, would changing it to like 75% make it dimmer or even brighter?

You would revert the left and right DRL lamp config back to stock. Then change the Dim duty cycle to whichever you desired.

Stock DRL Fixed Bright is 100%
Stock DRL Fixed Dim is 10%
You would just be setting the brightness of the dim from 10% to whichever you want. I currently have mine at 75%.

 

[ROBB1]

I think I misread a post. I decrease of duty cycle should have the effect of less light output. I also don't know why it would help with the flicker sense it should make it at least on paper flicker more but if the output was being dragged down then a decrease of duty cycle would help with flicker at that point.

My bad on misreading the post and taking it that it somehow implied that it kicked up the brightness when the post was referring to it was still bright.

You are correct in everything you were thinking and the on paper part.

Factory there are two duty cycles:
DRL only (bright) = 100%
Parking or Headlights on (dim) = 10%

One would hope that Ford designed the LEDs to handle 100% since a significant portion of the trucks life will be daytime / DRL only at 100%.

The original mod (and the one that seems to work for most but not all without flicker) basically tells the system to use bright in all conditions.

Anecdotally, the flicker seems to happen to people with the projector LED headlamps. They are for sure going to have higher current demands on the BCM with the adaptive actuators when headlamps are active. My theory is we are bumping up against the BCM's max current capability in these trucks when all of the exterior lights are on.

We are now trying a different approach to achieve a similar result. Bumping up the dim duty cycle, but stopping short of 100%.

 

[antho]

This is going from 10% to 75%
The 10% just looks weird due to the camera.

 

[Jesse-Infotainment]

Well my question in regards to the current draw is this. The current draw for the projectors is not on the BCM.. Its the BCM b.. each side has a fuse dedicated to the lights. The output from the bcm is actually a turn on for a relay in the BCMB and the low beam output is a turn on to the module in the headllamp that has its power from external source the BCMB. I retrofitted the projectors into my halogen truck and know the circuit really well. The bcm has no real direct power draw of any consequence with the LED lights. In fact it would have more a power draw with halogen since those are driven directly from the BCM both high and low beam and fog light. THe LED fogs are powered by the BCMB the DLR wont even turn on without the power circuit from the fuses in the BCMB.

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