GMC Yukon XL front and rear turn signal bulbs utilize 7444NA and 7440NA bulb sizes for replacement applications. The replacement chart covers vehicle production spanning 2015 to 2023.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7440NA and 7444NA are the two bulb types specified for the GMC Yukon XL turn signals across the listed model years. Both conform to ANSI standards recognized in the United States and Canada.
Both bulb types share the T20 wedge form factor and natural amber glass construction, operating on a 12-volt electrical system.
The natural amber glass in both bulb types produces the amber turn signal color directly from the bulb itself, rather than relying on a colored lens to filter white light.
The 7440NA is a single-filament bulb rated at 21W, while the 7444NA is a dual-filament bulb rated at 21W and 5W. The second filament in the 7444NA allows it to serve an additional lighting function alongside the primary turn signal function.
The GMC Yukon XL (2015-2016) uses the 7440NA for both front and rear turn signals. The 2023 model year uses the 7444NA in both positions instead.
The 7440NA and 7444NA are not interchangeable despite sharing the T20 wedge base. The 7444NA carries a dual-filament design that the single-filament 7440NA does not replicate, meaning substituting one for the other would result in either a non-functional secondary filament or an incompatible socket connection.
The front and rear turn signal positions share the same bulb size within each model year covered by the specifications, meaning the 2023 Yukon XL uses a single bulb type across both positions.