DIY: Make 2015-2017 LS/LT headlights operate like a LTZ headlight (LED as DRL vice low beams)

[Tylus]

On my 2017 LT the DRL was the headlight low beams.

The LED strip only energized in park, or when the auto lights sensed it was dark enough for low beams to turn on. Then low beam + LED were on

I reversed that with my mod




It looks like with your 2018 units, we can confirm the LED strip is physically different

 

[dvpvic]

On my 2017 LT the DRL was the headlight low beams.

The LED strip only energized in park, or when the auto lights sensed it was dark enough for low beams to turn on. Then low beam + LED were on

I reversed that with my mod




It looks like with your 2018 units, we can confirm the LED strip is physically different

I would say the same about physically different LED strip. The odd part I find is the behavior of my DRL, low beams aren’t the DRL. Even with my original headlamps.

To make sure I’m clear on this, if I’m in Drive and e brake is not set the low beams should come on as DRL correct? Or perhaps the 2016 doesn’t even have DRL? The build date on VIN label says 12/15

Thanks for any feedback, just trying to figure this out.


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[Tylus]

With e brake set, put in drive. If low beams come on you have the weird DRL

If the LED strip comes on, you have LTZ harness. it may just be a build thing. My old LS was optioned exactly like an LT...minus the leather.


But then your pictures show the LED strip and it isn’t that bright. Put your headlight switch manually to the Running lights. Are you low beams on also (even though shouldn’t)?

 

[hcvone]

Nice work and pics are great, TY

 

[Kpwweb]

Well I’m new on here just got the wife a 2016 LT well equipped. I was looking up LED/HID options and stumbled on this LED DRL thread and done little research. I had a friend that has a set of 2018 non HID headlamps and swapped them in to see if they will work direct plug and play. Here’s what I found; on my rig DRL seems to be the led strips only. I don’t have any other lamps come on when in gear D/R etc. I then swapped in a single 2018 unit and left one original one. Attached is a pic that shows the brightness difference. I also took 12v directly to each unit and they lit up as the function while on vehicle which shows that’s there’s no funky pwm going on. Not sure if I have some kind of mod. It come from a family that had it serviced at dealers etc so no one did any mods to my knowledge. I have RPO codes X88 and Y86 I think one of these is tied with the DRL option that I saw OP post about. Anyone know what I’m missing? Anyone on here have a 15-17 that could describe how their DRL functions? Because I think I’m just going to keep the 18’ set on and have the brighter LEDs. You can also see a slight color shift towards the cooler spectrum on the brighter LED

View attachment 224161


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It looks like you have an LTZ based on the grill and the way the DRL work?

 

[dvpvic]

It looks like you have an LTZ based on the grill and the way the DRL work?

No I just bought an LTZ grill from eBay and slapped it in. I like the looks of I’d better than the honeycomb one.


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[bradac]

Well I’m new on here just got the wife a 2016 LT well equipped. I was looking up LED/HID options and stumbled on this LED DRL thread and done little research. I had a friend that has a set of 2018 non HID headlamps and swapped them in to see if they will work direct plug and play. Here’s what I found; on my rig DRL seems to be the led strips only. I don’t have any other lamps come on when in gear D/R etc. I then swapped in a single 2018 unit and left one original one. Attached is a pic that shows the brightness difference. I also took 12v directly to each unit and they lit up as the function while on vehicle which shows that’s there’s no funky pwm going on. Not sure if I have some kind of mod. It come from a family that had it serviced at dealers etc so no one did any mods to my knowledge. I have RPO codes X88 and Y86 I think one of these is tied with the DRL option that I saw OP post about. Anyone know what I’m missing? Anyone on here have a 15-17 that could describe how their DRL functions? Because I think I’m just going to keep the 18’ set on and have the brighter LEDs. You can also see a slight color shift towards the cooler spectrum on the brighter LED

View attachment 224161


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So based on this logic,

I have a 2016 Tahoe LS, if I add a harness to convert the DRL from Low beam to LED strip, and then install 2018 standard headlights, I should have full led brightness as the headlight is on the passenger side in your pic?

 

[bradac]

Hey guys, just an update,

I installed the 2018 Tahoe headlights with the brighter LED stripe on my 2016.

With the harness I got from Matt, Which will swapped the standard DRL low beam to the LED, the problem is this doesn’t let the 2018 headlight run at max brightness with this harness.

Whats really interesting, is if I switch the Parking lights on, and remove the pigtail harness from matt, and just connect it directly like the normal headlight I can get Max brightness with the 2018 headlight I installed in parking light mode. This also happens when I remote start the car. However when the car is in drive without the harness it’s just low beam.

My guess it has todo with relays or not sending enough power. Maybe someone could answer this? I know a BCM reporgram would prob fix it, but looking for alternative solutions.

Attached is the photo of my 2016 with 2018 headlight with max brightness with Parking lighting engaged, when I put it in drive just switches the low beam on.

The downfall to using the parking lights engaged, is no auto headlights, having to turn it on and off, and the rest of the parking lights being engaged in the vehicle during the day.

 

[NappyBoy]

dude i willing to buy the harness you made if you could DM a paypal link and how much you need for those and i will give you my address to ship em

 

[cmatt]

Hey guys, just an update,

I installed the 2018 Tahoe headlights with the brighter LED stripe on my 2016.

With the harness I got from Matt, Which will swapped the standard DRL low beam to the LED, the problem is this doesn’t let the 2018 headlight run at max brightness with this harness.

Whats really interesting, is if I switch the Parking lights on, and remove the pigtail harness from matt, and just connect it directly like the normal headlight I can get Max brightness with the 2018 headlight I installed in parking light mode. This also happens when I remote start the car. However when the car is in drive without the harness it’s just low beam.

My guess it has todo with relays or not sending enough power. Maybe someone could answer this? I know a BCM reporgram would prob fix it, but looking for alternative solutions.

Attached is the photo of my 2016 with 2018 headlight with max brightness with Parking lighting engaged, when I put it in drive just switches the low beam on.

The downfall to using the parking lights engaged, is no auto headlights, having to turn it on and off, and the rest of the parking lights being engaged in the vehicle during the day.

View attachment 226250

The light behavior with and without my harness makes sense. On 15-17 models, the headlamp DRLs are ran at a reduced brightness via PWM voltage.

You’ve confirmed the LED strip in the 18+ headlights is different from the older models.

When you turn your headlamps on, do the LED strips dim on the 18+ headlights?


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