The GMC Canyon brake light utilizes 7440, 7443, and 3057 bulb sizes depending on the specific production period for the vehicle. Information provided covers a span from 2004 through 2024.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC Canyon brake light specifications reference three distinct bulb types across its model years: the 7440, 7443, and 3057 for the main brake position, and the 921 and 912 for the Center High Mount Stop Light.
The 7443 is the most frequently specified bulb across the Canyon lineup. It is a dual-filament T20 wedge bulb rated at 12V with a 21W high filament and a 5W low filament, making it suitable for combined stop and tail light functions.
The 7440 shares the same T20 wedge form factor as the 7443 but carries only a single filament rated at 21W. Because the 7440 lacks a second filament, it is not a drop-in replacement for positions that require the dual-filament 7443.
The 3057 is a dual-filament T25 wedge bulb rated at 12V, 27W/7W. Its T25 housing is physically larger than the T20 housing used by the 7440 and 7443, which means the two groups are not interchangeable despite both being dual-filament types.
The GMC Canyon (2004-2012) uses the 3057 for the main brake position, while model years 2015-2021 use the 7443. The 2023-2024 model years shift to the 7440 for that same position, representing a change from dual-filament to single-filament at the main brake location.
The 921 and 912 are both T15 wedge bulbs operating at 12V. The 912 is a variant of the 921 but is rated at 12W compared to the 921's 16W. The wattage difference means the two are not electrically identical, and substituting one for the other may affect light output.
The Center High Mount Stop Light on the GMC Canyon (2004-2012) uses the 912, while model years 2015-2021 and 2024 use the 921. The 2023 model year specifies the 7443 for that same position, which is a T20 wedge type rather than a T15.
The 2021 Canyon Center High Mount Stop Light specification includes a "Left And Right" qualifier for the 921 bulb, indicating that position involves two separate bulb sockets rather than a single unit.
The Outer Brake sub-position on the GMC Canyon is specified only for 2017-2019, with the 7443 listed for all three of those years.
All five bulb types listed in the Canyon brake specifications conform to ANSI standards applicable in both the United States and Canada, meaning they follow a shared North American sizing and designation system.