2019 GMC Yukon Bulb Sizes: Comprehensive Guide & Replacement Tips

As an ASE-certified master technician, I’ve worked on countless full-size GM SUVs, and the 2019 GMC Yukon is a frequent visitor in the shop. Whether you're driving the base SLE, the well-equipped SLT, or the top-tier Denali, having optimal lighting is crucial for a vehicle of this size.

The 2019 Yukon represents the later years of its generation (2015–2020), which means GMC started heavily integrating LED technology, especially in the higher trims. Below is the comprehensive guide to the bulb sizes for the 2019 GMC Yukon, along with replacement tips and upgrade considerations.

Quick reference

Note: Trim levels heavily dictate your bulb sizes. The Denali trim typically features factory High-Intensity Discharge (HID) or LED lighting, while lower trims (SLE/SLT) may still utilize standard halogen bulbs for certain functions.

LED vs halogen upgrade considerations

Upgrading your 2019 GMC Yukon’s halogen bulbs to LEDs is incredibly popular, but it isn’t always a simple plug-and-play process. GM’s electrical system uses a CANBUS (Controller Area Network Bus) to monitor bulb health.

• CANBUS Errors: If you swap an H11 halogen for an aftermarket LED without a CANBUS decoder, the system may think the bulb is burnt out because LEDs draw significantly less power. This can lead to dashboard warning messages or a rapid flickering effect (hyper-flashing).
• Hyper-flashing: If you replace your front 7443 turn signals with LEDs, you will almost certainly need to install load resistors in parallel with the wiring, or purchase premium LED bulbs with built-in resistors to prevent the blinker from flashing at double speed.
• Projector Housings: If your Yukon has halogen projector lenses, ensure you buy an LED bulb designed to cast light in a 360-degree pattern. Poorly designed LEDs in projector housings will result in dark spots and poor throw distance down the road.

How to replace each bulb

Here are a few quick tips from the bay on how to tackle these replacements:

• Headlights (Low/High Beam): GM didn't make this incredibly easy. On the 2019 Yukon, accessing the back of the headlight assembly requires removing the upper air baffle (the plastic trim under the hood) and partly loosening the front grille and bumper cover to slide the headlight housing forward. If you have the D3S HIDs, disconnect the battery first, as HID ballasts generate lethal voltage.
• Fog Lights: These are best accessed from underneath the vehicle or by turning the front wheels all the way inward and pulling back the wheel well liner.
• Front Turn Signals: Similar to the headlights, these are housed in the main assembly. You can sometimes reach them by removing the air box on the passenger side or reaching down on the driver's side, but housing removal is often easier for those with larger hands.
• Tail, Brake, and Rear Turn Signals: Good news and bad news. The bad news: they are completely sealed LED units from the factory. If a brake light goes out, you have to replace the entire tail light assembly. The good news: they rarely burn out.
• Reverse Lights: Dropping the tailgate and removing the two screws holding the tail light assembly will allow you to pull the housing out and access the reverse light socket easily.
• License Plate / Interior Bulbs: Use a plastic non-marring pry tool to pop off the license plate lenses and the interior dome covers. The 194 bulbs pull straight out.

Common lighting issues for this generation

The 2015-2020 generation of GM SUVs is notorious for a specific lighting flaw: the factory LED tail lights. It is very common for the LED strips in the brake or tail light to fail prematurely due to a cracked solder joint on the internal circuit board. Because the housing is sealed, the official fix is a complete replacement of the assembly, which can be pricey.

Additionally, moisture intrusion in the front headlight assemblies can occur if the rear dust caps are not seated properly after a bulb change, leading to condensation that can burn out HID ballasts or halogen bulbs.

If you are dealing with a dead factory LED tail light assembly, or if pulling the front bumper cover to change a headlight bulb feels outside your comfort zone, don't risk snapping expensive plastic clips. Find a trusted shop on Repairius.