For the 2019 Cadillac CT6, both the low-beam and high-beam headlights use integrated LED lighting. The supplied fitment data does not identify a replaceable halogen headlight bulb or indicate a projector versus non-projector headlight variation, so confirm the complete headlamp assembly before ordering replacement parts.
Other exterior lighting is also LED-equipped, including the front turn signals, brake lights, center stop light, daytime running lights, license plate lights, parking lights, front and rear side markers, tail lights, and rear turn signals. No fog-light bulb fitment is listed.
The reverse lights use a 921 bulb. Trunk lighting may use either a 194 or 7441 bulb, indicating a possible fixture or equipment variation; check the existing bulb before purchase. The vanity light uses an 6612F bulb. Because most exterior lamps are listed as LED, replacement may involve an LED module or lamp assembly rather than a conventional interchangeable bulb.