How to confirm if a new Sierra has the High Performance LED Headlamps

Aldila · July 13, 2016

Mine says PDP=LED healights

Silvern Sentry · July 13, 2016

Why in the world some of yall are telling him to pull pieces off his truck to find out the headlights is beyond me. If it came with the option on the sticker, it has them. Otherwise as 15HD said, look at the RPO code, pretty simple...

Those that are telling him different difficult ways to find out by pulling parts out, how do you check what gears you have? Do you pull your diff cover off and start counting?

Tyler

My mistake I had thought he was going for a manual inspection and wanted to see the difference with own eyes.

Besides that valence is meant to be removed and takes naught but a couple minutes. Besides those people without LED might actually need to change a light bulb sometime. But hey if you are the type that needs to book shop time to change a wiper blad by all means you do you.

1300c · July 13, 2016

Why in the world some of yall are telling him to pull pieces off his truck to find out the headlights is beyond me. If it came with the option on the sticker, it has them. Otherwise as 15HD said, look at the RPO code, pretty simple...

Those that are telling him different difficult ways to find out by pulling parts out, how do you check what gears you have? Do you pull your diff cover off and start counting?

Tyler

LOL I could see how that came across like that. I'm just saying they are sealed so it wouldn't be worth the hassle to do that. I am interested in what the module looks like though. Give it enough time and someone will modify one. The sad thing is the salesman the OP talked about should've known about the codes, or at least where they are so he could look them up for the customer.

TxTruckMan · July 13, 2016

1) You will need a trim puller to remove the large plastic valence when you open up the hood.

2) On drivers side you should be able to access the headlamp now. Passenger blocked by Air intake.

3) Remove the back cover piece, should screw off.

4) Light should have a fan (some LED headlamps have a thick copper/metal braid for cooling but i do not believe these do)

5) Report back

LED uses same housings as HID so looks same from outside.

You're spreading incorrect information again. The 2016 LED headlights are sealed and cannot be accessed like the 2014/2015 headlights. There is no bulb to replace.

camcamaro1991 · July 13, 2016

My Denali RPO code is T4L for LED

newdude · July 13, 2016

From the order guide.

RPO code for 2016 sierra SLT LEDs is PDP:

PDP NEW! Headlamps, high-performance LED headlamps with GMC signature LED lighting

The standard lights are HID's:

T4F NEW! Headlamps, high intensity discharge (HID) projector-beam with LED signature

In early production, the T4F was not available on SLT (but was installed on the other trims).

(all early SLT's were LED, and LED is still included on SLT's with (PDT) SLT Crew Cab Premium Plus Package and (STF) All Terrain X Package)

T4F is HID

PDP is the LED's

http://www.gmfleetorderguide.com/NASApp/domestic/proddesc.jsp?year=2016&regionID=1&divisionID=2&type=0&vehicleID=17967&section=oi_def&page=4&butID=3

Mine says PDP=LED healights

Some clarification on the PDP T4L deal:

The RPO codes for LED headlights is T4L. All Denali trucks have this code, as do SLT trucks. Where PDP comes into play is on SLE and SLT trim level trucks. HID lighting (T4F) is standard equipment on both SLE and SLT trim. On SLE, if you order the All Terrain package, you get the T4L LED lighting. On SLT trucks, T4L lighting is part of the SLT Premium Plus Package and All Terrain package. PDP is just an ordering code if you will to signify that the truck was up-optioned to have the LED lighting over the standard HID lighting. PDP is not the direct RPO code for LED headlights.

I ran multiple VIN numbers, Denali and SLT. SLT trucks with LED lighting had T4L and PDP listed in the build, and Denali trucks just had T4L as they have LED headlights standard.

So...to clarify, T4F is HID and T4L is LED. PDP is a secondary signifier that the truck was optioned up to T4L LED headlights via one of the available packages that include the LED headlights.

T4F - HID

T4L - LED

PDP - Truck has All Terrain, All Terrain X, or SLE Premium Plus.

Silvern Sentry · July 13, 2016

LOL I could see how that came across like that. I'm just saying they are sealed so it wouldn't be worth the hassle to do that. I am interested in what the module looks like though. Give it enough time and someone will modify one. The sad thing is the salesman the OP talked about should've known about the codes, or at least where they are so he could look them up for the customer.

Thanks for mentioning they are sealed that is a good point and i did not know and how is a user to know without looking. Seems like a bad choice IMO like I am no engineer but I know they can fail and not a decades old proven technology yet. Chances are you may never need to maintain them but at some point someone will and I feel bad for the poor bugger that has to stick his whole headlight in an oven and crack it open just to check if a part is fried and swap the bulb 7-10 years from now that or he is stuck replacing whole housing for like whatever outrageous up marked price gm will charge.

DAY11 · July 13, 2016

For those curious it seems that the Chevy codes are different on this one. No T4? on my list

TJay74 · July 13, 2016

Thanks for mentioning they are sealed that is a good point and i did not know and how is a user to know without looking. Seems like a bad choice IMO like I am no engineer but I know they can fail and not a decades old proven technology yet. Chances are you may never need to maintain them but at some point someone will and I feel bad for the poor bugger that has to stick his whole headlight in an oven and crack it open just to check if a part is fried and swap the bulb 7-10 years from now that or he is stuck replacing whole housing for like whatever outrageous up marked price gm will charge.

LED and Laser lighting technology has been in use for many years, mostly in Europe. Heck in Europe laser lighting is big over there as it has way higher output and really lights the road up. I know BMW has a system over there that uses laser and also can automatically sense other cars and dim or reduce the output when needed. They aren't allowed over here because the USA DOT still uses archaic specs from the 1960's for output of head lamp bulbs.

Another way you can tell if it is LED, if you face the headlamps head on at the right angle you can see the square LED elements reflect from the projector lens.

Silvern Sentry · July 13, 2016

You are right but think the BMW are removable http://www.weisslicht.com/claims to only make them for BMW. But not like I own one perhaps the very latest models is not.

FVMSS article 108 (external lights) was actually updated in 1989. Still archaic given all the development in new tech. And again in 2007 to update it to MS Word format. Someone literally spent more time formatting it in the last 30 years then reviewing and updating it. You can Google FMVSS 108 and read the revision log. Sad what the government has become in everyone's business and not doing the stuff they should like regulating new tech properly.

newdude · July 13, 2016

For those curious it seems that the Chevy codes are different on this one. No T4? on my list

Yea there is something up on the Chevy side. A LTZ Z71 VIN number had T4L on the build sheet, but a High Country and an LTZ I ran didn't. It could be because they are standard equipment but that is strange because the Denali has it listed on the build but and LTZ and High Country don't.

1300c · July 13, 2016

LED and Laser lighting technology has been in use for many years, mostly in Europe. Heck in Europe laser lighting is big over there as it has way higher output and really lights the road up. I know BMW has a system over there that uses laser and also can automatically sense other cars and dim or reduce the output when needed. They aren't allowed over here because the USA DOT still uses archaic specs from the 1960's for output of head lamp bulbs.

Another way you can tell if it is LED, if you face the headlamps head on at the right angle you can see the square LED elements reflect from the projector lens.

Exactly you can see the 3 chips lit up when looking at my projector lense at an angle.

Reidan · July 13, 2016

Thanks for all the excellent information. I like you guys already!!

I keep forgetting to check the glove box to check the As Built codes. I will do it when I leave work or once I get home.

So, if units are sealed. Assume the only way to replace a defective LED chip is to exchange the entire assembly? Wow, that sounds expensive! Hopefully these things never burn out.

redwngr · July 13, 2016

Some clarification on the PDP T4L deal:

The RPO codes for LED headlights is T4L. All Denali trucks have this code, as do SLT trucks. Where PDP comes into play is on SLE and SLT trim level trucks. HID lighting (T4F) is standard equipment on both SLE and SLT trim. On SLE, if you order the All Terrain package, you get the T4L LED lighting. On SLT trucks, T4L lighting is part of the SLT Premium Plus Package and All Terrain package. PDP is just an ordering code if you will to signify that the truck was up-optioned to have the LED lighting over the standard HID lighting. PDP is not the direct RPO code for LED headlights.

I ran multiple VIN numbers, Denali and SLT. SLT trucks with LED lighting had T4L and PDP listed in the build, and Denali trucks just had T4L as they have LED headlights standard.

So...to clarify, T4F is HID and T4L is LED. PDP is a secondary signifier that the truck was optioned up to T4L LED headlights via one of the available packages that include the LED headlights.

T4F - HID

T4L - LED

PDP - Truck has All Terrain, All Terrain X, or SLE Premium Plus.

That's NOT what the fleet order guide says for SLT.

Even the PDT option package (SLT Crew Cab Premium Plus) refers to the LED lights as PDP.

Cut and paste:

PDT NEW! SLT Crew Cab Premium Plus Package, Requires Crew Cab model. Includes (NZP) 20" chrome clad wheels, (UD5) Front and Rear Park Assist, (UVD) heated steering wheel, (A48) power sliding rear window, (BVQ) 6" rectangular chrome tubular assist steps, (UQA) Bose premium audio system, (IO6) IntelliLink 8" Diagonal Color Touch audio system with Navigation, (Y86) Enhanced Driver Alert Package, (AN3) front bucket seats, (KB6) heated and vented seating, (CGN) spray-on bed liner and (PDP) full LED headlamps.

1 - Not available with (PCM) SLT Preferred Package, (PDG) All Terrain SLT Premium Package, (PDB) SLT Premium Package, (PDC) Texas SLT Premium Package, (GAT) All Terrain Package, (NHT) Max Trailering Package or any LPO wheels. Note: No changes or substitutions to the included Premium Plus Package equipment will be allowed. If not specifically mentioned as not available as above, all other normally available 4SA options will be allowed.

And PDP entry cut and paste separately:

PDP NEW! Headlamps, high-performance LED headlamps with GMC signature LED lighting

SLE - Requires and only available with (GAT) All Terrain Package.

SLT - Included with (PDT) SLT Crew Cab Premium Plus Package and (STF) All Terrain X Package

Silvern Sentry · July 13, 2016

Thanks for all the excellent information. I like you guys already!!

I keep forgetting to check the glove box to check the As Built codes. I will do it when I leave work or once I get home.

So, if units are sealed. Assume the only way to replace a defective LED chip is to exchange the entire assembly? Wow, that sounds expensive! Hopefully these things never burn out.

They should last a long long time for sure but certainly not indefinitely, they can also potentially fail early of course. You can unseal headlights but even then that is a messy messy job (you bake them in like an oven till the glue/sealant goes soft and rip it open*) for something that was once as simple as changing a light bulb. GM's track record with headlamp design has certainly left a lot to be desired this last few years not sure I would trust it to 'last the life of the vehicle' but I could be bias.

* at least that is how you normally do it. Before you know Black03Yukon wants to jump at me saying I do not know anything about this new tech while he is still trying to change a tire and scrape together this months car note payment