GMC Terrain high beam headlight bulbs utilize D5S or 9005 sizes, while low beam headlight bulbs use D5S or H11 sizes depending on model configuration. The replacement chart covers 2010 through 2021 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The D5S is a High-Intensity Discharge bulb that operates on xenon gas rather than a heated filament. It follows the ECE standard recognized across Europe and worldwide, runs at 12V and 25W, and uses a PK32d-7 base. Its low wattage relative to halogen types reflects the higher luminous efficiency of gas-discharge technology.
The GMC Terrain uses the D5S for both high and low beam positions in 2021, and in 2019-2020 this bulb is designated specifically for vehicles equipped with HID headlamps. In 2018, the D5S also appears as a dual-position bulb but only under the same HID headlamp condition.
The 9005 is an ANSI-standard single-filament halogen bulb with a P20d base, rated at 12V and 65W. It is the high beam bulb for the Terrain across 2010-2017, and also applies to the standard (non-HID) 2018 configuration.
The H11 is an ECE-standard single-filament halogen bulb with a PGJ19-2 base, rated at 12V and 55W. Although it originates from the ECE framework, it carries US approval as well. It serves as the low beam bulb for the Terrain from 2010 through 2017, and in the non-HID 2018 variant.
The 9005 and H11 are not interchangeable despite both being 12V halogen types. They use different base configurations, the P20d and PGJ19-2 respectively, and carry different wattage ratings, which reflects their distinct roles as high and low beam bulbs.
The D5S is similarly non-interchangeable with either halogen type. Its PK32d-7 base, discharge ignition requirement, and dedicated HID ballast circuitry make it incompatible with housings designed for the 9005 or H11.
For 2018 Terrain vehicles, two separate fitment paths exist for both the high and low beam positions. The correct bulb type depends on whether the vehicle was built with HID headlamps, making headlamp system verification a necessary step before selecting a replacement bulb.