Why Do GMC Trucks Have Such Terrible Headlights?

Posted on
Scott McCracken
#lights #tsb

GMC Sierra owners are seeing red. Well, technically they're not seeing anything. That's the problem.

The headlights in the 3rd generation (2014–present) are so dim, you'd probably get better illumination from a jar of fireflies taped to the bumper. GMC changed the design for 2016, leaving owners of previous model years wondering if they'll be left in the dark?

GM Changed Their Headlight Design for 2014

In prior model years, GM used three different bulbs for the Sierra's headlights --- a H11LL bulb for the low beams, a 9005LL bulb for the high beams and a 5202 bulb for the fog lights.

But starting with the 2014 model year, GM switches to one 9012 halogen single filament bulb for both the low and high beams. Historically, automakers have at least used dual-filament bulbs for low / high beams.

"The headlights are terrible, low beams are absolutely useless and high beams are only slightly better."

For 2016, GM "refreshed” the Sierra design with a new grille, front fascia and yep ... headlight design.

Common Complaints About the Sierra Headlights

  • Driving at night, especially in the rain, can feel very dangerous
  • The light output and beam pattern are both terrible, providing very little lateral illumination
  • The design uses a single (crappy) projector for both low and high beams, with just a shutter that raises for high beam.
  • $40-50k trucks shouldn't come with budget headlights

Not a Bright Sight
Owner submitted photo of dim headlights

IIHS Says News Truck Headlights Are Terrible

Turns out it's not just the Sierra, because according to the IIHS pretty much all new truck headlights are terrible. In fact, the more expensive the truck the worse the stock lights.

The Institute tested headlights on small and large 2016-2017 pickups and found the most expensive trucks are the vehicles that come equipped with the poorest headlights. And out of the four small pickups and seven large pickups tested, only one truck achieved a "good" rating for the headlights.

The 2016 and 2017 Sierra earned “acceptable" ratings. That seems a little optimistic.

GM Issued Instructions to Dealers on How to Fix the Problem

On March 1st, 2015, GM released TSB #PIT5374 to its dealers titled Headlight Performance (BCM Calibration and Bulbs). Technical service bulletins (TSBs) are a set of instructions on automaker sends to its dealers about how to handle specific problems.

Here's how it starts:

Some customers may comment of poor headlight performance when driving in very dark rural areas. While the headlights meet all Federal Motor Vehicle Safety Standard (FMVSS) requirements and Canada Motor Vehicle Safety Standard (CMVSS) requirements, customers may request better headlight performance for these very dark rural areas.

OK, two things here:

  1. Aren't very dark rural areas where you need dependable headlights the most? Mentioning this twice seems odd.
  2. Know your target market. Farmers and blue-collar workers --- who hey, by the way, live in these "very dark rural areas" --- are one of the biggest buying groups for your trucks.

The TSB goes on to make the following recommendations once the headlights have been diagnosed to be working properly:

  1. For vehicles built before 12/23/14 at Flint Assembly (11th VIN digit "F"), 1/13/15 at Silao Assembly (11th VIN digit "G"), or 1/1/6/15 at Ft. Wayne Assembly (11th VIN digit "Z"), reprogram the BCM with the latest calibration available in TISWEB starting on 1/1/2/15. The new BCM calibration will increase the voltage to the headlight bulbs in both low and high beam selections.

The BCM is the body control module which is a generic term for a control unit that monitors and controls electronic accessories, like the headlights, on a vehicle. The TSB says that vehicles built after the referenced dates already get the increased voltage.

  1. Replace both headlight bulbs with updated bulb part number 23342527 ... After bulb replacement, perform Headlamp Aiming Procedure.

Ah, ha! New headlights made by Vosla. Now we're starting to see the light.

There Are Still Class-Action Lawsuits About the Headlights

In late 2015 a class-action lawsuit was filed claiming Sierra 1500 owners can't drive at night because of the defective headlights. The lawsuit points to GM's TSBs and the recent redesign as evidence that GM knows how bad this problem really is.

"Brand new GMC Sierra truck that I am afraid to drive an night. First thought that my eyes suddenly were falling apart or my windshield was tinted, but these headlights are the worst I have ever seen (or more correctly, not seen) on a vehicle."

"I have owned eleven vehicles in my lifetime and these are the worst headlights I have experienced. A very short cutoff and worst of all, no side illumination. --- 2014 Sierra 1500 owner"

But General Motors Wants Them Dropped

GM wants the charges against them dropped and it's not because they're standing behind their product. The main points of GM's argument are all legal hurdles:

  1. None of the lawsuits are claiming the lights are malfunctioning in any way
  2. The lawsuits talk about how the dim lights will lead to more nighttime accidents without showing any data to back it up
  3. The plaintiffs aren't accusing GM of making any inaccurate statements about the brightness of the lights

For now, the case remains open in a California

Generations Where This Problem Has Been Reported

This problem has popped up in the following GMC generations.

Most years within a generation share the same parts and manufacturing process. You can also expect them to share the same problems. So while it may not be a problem in every year yet, it's worth looking out for.

Further Reading

A timeline of stories related to this problem. We try to boil these stories down to the most important bits so you can quickly see where things stand. Interested in getting these stories in an email? Signup for free email alerts for your vehicle over at CarComplaints.com.

  1. A lawsuit regarding the GMC Sierra’s “inadequate” headlights is still burning bright in a California court.

    The plaintiffs allege GM made changes in the bulbs, assemblies and operation of the headlights … GM allegedly changed to projector-style headlights with single bulbs, smaller reflectors, two lenses each and shutters to switch between high and low beams that work from a single voltage source.

    The lawsuit was filed back in 2015 after owners started questioning GM’s headlight redesign for the 2014 and 2015 model years.

    Look – if you saw one of these trucks driving in the oncoming lane at night, I wouldn’t blame you if you confused it for a pair of mopeds with weak batteries. It’s that bad.

    keep reading article "The Sierra’s Dim Headlights Are Under a Spotlight"
  2. GM isn't arguing against claims that the 2014-2015 GMC Sierra has some terrible headlights

    , just that the lawsuits against them don't prove it. GM argues truck owners don't allege the lights malfunction in any way, so the case should be dismissed because other lawsuits have been dismissed because of similar claims.

    The plaintiffs are worried ineffective lights will lead to more nighttime crashes, but GM says they have no data to back it up. If the automaker actually needs data for that, then I'm not sure which is dimmer --- the headlights or GM itself.

    keep reading article "GM Wants Sierra Headlight Lawsuits Dropped"

OK, Now What?

Maybe you've experienced this problem. Maybe you're concerned you will soon. Whatever the reason, here's a handful of things you can do to make sure it gets the attention it deserves.

  1. File Your Complaint

    CarComplaints.com is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases.

    Add a Complaint
  2. Notify CAS

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits.

    Notify The CAS
  3. Report a Safety Concern

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues.

    Report to NHTSA