The Cadillac XLR high beam and low beam headlight bulbs both utilize the D1S bulb size. The replacement chart covers vehicle production spanning 2004 to 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Cadillac XLR uses the D1S bulb type across all listed model years (2004-2009) for both high beam and low beam headlight positions.
The D1S is a High-Intensity Discharge (HID) xenon bulb, operating at 85 volts and 35 watts, which places it in a different electrical category than conventional halogen bulbs.
D1S bulbs feature a PK32d-2 base with an integral ignitor built directly into the bulb unit, meaning the ignitor and bulb are replaced as a single assembly rather than as separate components.
The D1S designation is specific to projector-type headlight housings, and the bulb is not interchangeable with reflector-type housing applications without modification to the housing itself.
The D1S standard falls under ECE regulation, indicating it conforms to European and international lighting specifications rather than SAE standards used in some North American-only applications.
Because the Cadillac XLR uses the same D1S bulb for both the high beam and low beam functions, the headlight system relies on a single bulb per housing to serve both lighting roles, which is characteristic of certain projector-based HID configurations.