For the 2016 Cadillac CTS, both the low-beam and high-beam headlights use D3S bulbs. The supplied fitment data does not list a separate halogen headlight option or a fog-light bulb, so verify the existing housing and connector before ordering.
- Exterior lighting: Front and rear turn signals, brake lights, center stop light, daytime running lights, tail lights, and front and rear side markers are LED applications.
- Reverse lights: Use 921 bulbs.
- License plate and dome lights: The data lists both 2825 and 98 bulb options, so check the installed bulb or socket for the correct choice.
- Interior lighting: The glove box and general interior use 906 bulbs, map lights use PC175, the trunk uses 211-2, the vanity light uses 6612F, and the step light uses 2886X.
Because many exterior functions are LED-equipped, replacement may involve an LED assembly rather than a conventional replaceable bulb. Confirm the original part before purchasing.