In short: if your 2013 ATS has HID headlights, the low-beam bulbs are typically D3S with a ballast and the high beams are a separate 9005 bulb. If your car is equipped with halogen headlights, the low beams are typically H11 and the high beams are 9005.
The 2013 Cadillac ATS offered two main headlight configurations depending on trim and options. The exact bulb type can vary by market and production date, so it’s important to verify the specific bulb in your vehicle by checking the owner's manual, the headlamp label, or the bulb itself.
Two main headlight configurations in the 2013 ATS
Most owners will encounter one of two configurations for the 2013 ATS: HID-based headlights or traditional halogen headlights. Each uses a different bulb family for the low-beam function, while high beams generally use a common halogen type across configurations.
- HID low-beam headlights: D3S bulbs (with an accompanying ballast). The high beams, when separate, are typically standard halogen bulbs such as 9005.
- Halogen low-beam headlights: H11 bulbs. The high beams are typically 9005 (HB3) in many GM configurations.
Note: These configurations cover the most common setups for the 2013 ATS. Actual bulb types can vary by production date, trim level, and regional market. Always confirm by inspecting the headlight assembly or checking the vehicle's manual.
How to confirm your specific bulb type
To be certain of the exact bulb in your vehicle, use these steps to identify and replace with the correct part number:
- Check the owner's manual or the service manual for the recommended bulb specification for your trim and region.
- Inspect the headlight housing label or the back of the bulb socket for part numbers (for HID, you may see D3S; for halogen, you may see H11 or 9005).
- Physically remove the headlight bulb assembly (with the vehicle off) and compare the bulb base and connector to known standards (D3S vs D1S/D2S vs H11 vs 9005).
- If in doubt, contact a Cadillac dealership parts department with your VIN to confirm the exact bulb type and replacement part numbers.
Replacement tips: When replacing HID bulbs, avoid touching the glass with bare hands to prevent oil contamination. If you must handle the bulb, wear gloves or use a clean cloth. Ensure the ballast system is functioning, as HID systems rely on a ready ballast to ignite and regulate the arc.
Summary
The 2013 Cadillac ATS uses two main headlight bulb configurations: HID low beams typically use D3S bulbs, high beams use 9005, and halogen low beams use H11 with 9005 high beams. Exact bulb type depends on trim and options, so verify via the manual or by inspecting the headlight assembly or contacting a dealer.