Cadillac HID Headlight Bulb Guide — D1S, D2S, D3S Replacement for ATS, CTS, DTS, Escalade, SRX, XTS

Cadillac HID Headlight Bulb Replacement Guide

Cadillac factory HID headlamps span three bulb families across roughly two decades. The DTS and early CTS used D1S (Osram 66144, Philips 85410; Cadillac/GM OE 25806714). The SRX uses D2S (Osram 66240, Philips 85122). The ATS, Gen 3 CTS and XTS use the mercury-free D3S (Osram 66340, Philips 42302). D1S, D2S and D3S are not interchangeable — each runs on a different ballast voltage and base design. Always confirm the D-code stamped on your existing capsule before ordering. Many Cadillac models in the same year were also sold with halogen headlamps; this guide covers factory HID-equipped trims only.

Factory HID Models (Cadillac)

ATS
2013–2019 (HID-equipped trims) — D3S projector HID low-beam; base Luxury trims used halogen in the same years, so confirm you have the HID package before ordering.

CTS
Gen 2 (2008–2013) — D1S projector HID low-beam.
Gen 3 (2014–2019) including V-Sport and CTS-V — D3S projector HID low-beam. If your Gen 3 CTS shows a different code on the capsule, read it and confirm before ordering.

DTS
2006–2011 — D1S projector HID low-beam.

Escalade
GMT900 (2007–2014 Platinum with factory HID) — D1S projector HID low-beam; non-Platinum GMT900 Escalades use halogen.
K2XL (2015–2020) — CHECK MANUALLY by reading the bulb code; the K2XL generation moved to a new headlamp system and the correct bulb type should be confirmed at the housing before ordering. Call 647‑547‑1962 if you need help.

SRX
Gen 1 (2004–2009) — D2S HID low-beam.
Gen 2 (2010–2016 HID-equipped trims) — D2S HID low-beam; halogen trims use H11 and are not included in this guide.

XTS
2013–2019 (HID-equipped trims) — D3S projector HID low-beam.

Cadillac HID Headlight FAQs

My 2015 CTS has factory HID. What bulb does it use?
The 2014–2019 Gen 3 CTS (all trims including V-Sport and CTS-V) uses D3S. The 2008–2013 Gen 2 CTS uses D1S. Confirm by reading the code on your existing capsule before ordering.

My 2012 SRX has HID headlights. Is it D1S?
No — the 2010–2016 SRX uses D2S, not D1S. Some online listings incorrectly apply D1S to SRX models; confirm by reading the bulb code stamped on the capsule base.

Can I use D1S in a D3S ballast or vice versa?
No. D1S runs at 85V with an integrated igniter; D3S is mercury-free and runs at 42V. The bases are physically keyed differently so they will not seat in the wrong housing.

My 2013 ATS is a base model — does it have HID?
Not necessarily. The base Luxury trim ATS used halogen headlamps; HID was available on Performance and Premium trims. If your ATS has factory HID, it uses D3S. Check behind the headlamp housing for the ballast module — halogen cars will not have one.

Not sure which bulb your Cadillac needs?
The bulb type code is stamped on the base of the capsule. If you cannot access the bulb, send us your VIN or call 647‑547‑1962 and we will confirm the correct type before you order.