For the 2020 GMC Sierra 1500, the low-beam and high-beam headlights both use a D5S bulb. The supplied fitment data does not list a fog-light bulb for this model year.
Exterior lighting uses several different bulb sizes depending on the function:
- Front turn signals and parking lights: 7444NA
- Rear turn signals: 7444NA
- Brake and tail lights: 7444
- Reverse lights and center stop light: 921
- Rear side markers: 194NA
- License plate lights: 2825
Interior applications include a 921 trunk light and 6612F vanity light. Confirm the existing bulb and socket before ordering, particularly when replacing multiple lighting functions, since the 2020 Sierra 1500 uses different bulb numbers throughout the vehicle.