GMC Envoy high beam headlight bulbs use 9005 size while low beam headlight bulbs use 9006 size. The replacement chart covers 2002 through 2009 model 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 GMC Envoy uses the 9005 bulb for high beam headlights and the 9006 bulb for low beam headlights across all model years from 2002-2009.
Both the 9005 and 9006 are single-filament halogen bulbs operating on a 12-volt electrical system, which is standard for automotive applications of this type.
The 9005 bulb carries a 65-watt rating, while the 9006 runs at 55 watts, meaning the high beam draws more power and produces a brighter output than the low beam.
Although the 9005 and 9006 share a similar physical form, they have different base types. The 9005 uses a P20d base and the 9006 uses a P22d base, making the two bulbs non-interchangeable despite their visual resemblance.
Both bulb types conform to ANSI standards recognized in the United States and Canada, indicating they meet a defined set of performance and dimensional criteria for the North American market.
Because the Envoy uses separate bulbs for high and low beams rather than a dual-filament design, each function relies on its own independent bulb and socket, so a failure in one beam does not affect the other.