For most 2015 Terrain models with halogen headlights, the bulbs are H11 for low beams, 9005 for high beams, and H11 for fog lights. If your Terrain is equipped with factory HID headlights, the bulbs are HID-type bulbs (not the standard halogen codes) and require a ballast.
The exact bulb type can vary by trim and lighting package, so the best way to confirm is to check the owner's manual or inspect the headlight assembly label. Below, we outline typical configurations and how to identify yours.
Halogen headlights: standard on most trims
Most 2015 Terrain models use halogen headlights. Here are the typical bulb types tied to each headlamp function.
- Low beam: H11
- High beam: 9005 (HB5)
- Fog lights: H11
Note: Some regional or dealer-installed options may vary; consult the owner's manual or inspect the bulb label under the hood to confirm.
Factory HID headlights: rare but possible
If your Terrain is equipped with factory HID headlights, the bulbs are HID types and require ballasts. Bulb codes can vary by the exact headlamp assembly, but common HID options include D1S, D2S, or D3S for the low-beam portion. The high-beam in some HID setups may be separate HID or remain halogen depending on the package.
- Low beam: HID bulb (commonly D1S / D2S / D3S, depending on the assembly)
- High beam: often a separate bulb (may be halogen 9005 or HID, depending on option)
- Fog lights: typically different from HID headlamps (check the specific vehicle)
To avoid guesswork, check the under-hood label on the headlight assembly or the owner's manual for the exact bulb type.
How to confirm the exact bulb on your vehicle
- Open the owner’s manual and look up the headlight bulb replacement section.
- Inspect the bulb socket under the headlight housing for the stamped bulb type code.
- Check the label on the ballast or inside the headlight housing if you have HID headlights.
- Ask a GMC dealer or use the GM parts catalog by entering your VIN or trim.
Correct bulb identification reduces the risk of purchasing the wrong bulb and ensures proper fit and performance.
Summary
The 2015 GMC Terrain typically uses halogen H11 low beams, 9005 high beams, and H11 fog lights. If your vehicle has factory HID headlights, expect HID bulbs (D1S/D2S/D3S) with ballasts, and possibly different high-beam arrangements. Always verify with the manual or labeling on the unit to ensure you buy the right bulbs for your exact trim and option package.