What is the low beam headlight bulb size for a 2015 Cadillac ATS?

The 2015 Cadillac ATS uses a HID-D3S LED bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 2015 Cadillac ATS?

The high beam bulb size for the 2015 Cadillac ATS is HID-D3S LED.

Why are my 2015 Cadillac ATS headlights dim?

Dim headlights on a 2015 Cadillac ATS can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a HID-D3S LED LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2015 Cadillac ATS fog light?

The 2015 Cadillac ATS uses a LED Fog Light bulb for the fog light position.

Is the 2015 Cadillac ATS single or dual beam?

The 2015 Cadillac ATS uses a single bulb (dual filament) headlight system. This means one bulb controls both high and low beams.

Can I install LED bulbs on my 2015 Cadillac ATS?

Yes, the 2015 Cadillac ATS comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a HID-D3S LED LED conversion kit for the low beams.

Does the 2015 Cadillac ATS have fog lights?

Yes, the 2015 Cadillac ATS takes a LED Fog Light bulb for the fog light position.

How do I change the headlight on a 2015 Cadillac ATS?

Turn off the vehicle and open the hood. Locate the headlight assembly from behind, remove the dust cover or retaining clip, disconnect the wiring harness, twist the old HID-D3S LED bulb counter-clockwise to remove it, then insert the new bulb and reassemble. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 2015 Cadillac ATS?

LED bulbs used off-road or in auxiliary lights are legal everywhere. For on-road headlight use, legality varies by state. Many states allow LED retrofits as long as the beam pattern meets DOT standards. For the best legal compliance, choose a DOT-approved HID-D3S LED LED kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 2015 Cadillac ATS headlights?

A pair of HID HID-D3S LED bulbs costs $50 to $150. If you have a shop do the work, expect an additional $20 to $50 in labor per bulb. Replacing them yourself at home saves the labor cost and usually takes under 30 minutes.

What is the difference between halogen and LED for a 2015 Cadillac ATS?

Halogen bulbs produce a warm yellow light (around 3200K), last 500 to 1000 hours, and draw more power. LED bulbs emit a brighter white light (5000-6000K), last 25,000+ hours, and use less energy. LED upgrades for the HID-D3S LED position are available as direct plug-and-play replacements.

This vehicle is part of the 2014–2015 Cadillac ATS generation. All models in this range share identical light bulb sizes.

Fitment Guaranteed for 2015 Cadillac ATS

What Size Bulbs Does a 2015 Cadillac ATS Use?

Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.

Installation Difficulty

Easy (Plug and Play)

Est. Replacement Cost

$50 - $150 (HID System)

What Lighting System Does the 2015 Cadillac ATS Have?

Owners of the 2015 Cadillac ATS will find a total of 11 lighting elements throughout the vehicle's exterior. It features an extensive lighting system powered by premium factory HID/Xenon technology utilizing D3S projector housings for high-intensity output. This model belongs to the early years of the ATS's 2014-2019 production span.

Can You Put LED Bulbs in a 2015 Cadillac ATS?

The 2015 Cadillac ATS is already equipped with factory D3S HID/Xenon headlights. Since HID technology already provides exceptional brightness, we recommend staying with high-quality OEM replacement bulbs rather than attempting an LED retrofit for the primary headlights. However, the LED Fog Light fog lights are typically halogen and are excellent candidates for an LED upgrade to match the color temperature of your HID headlights.

2015 Cadillac ATS Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	HID-D3S LED	Buy HID-D3S LED →
High Beam	HID-D3S LED	Buy HID-D3S LED →
Fog Light	LED Fog Light	Buy LED Fog Light →
Brake Light	LED Bulb	Buy LED Bulb →
Side Marker	LED Bulb	Buy LED Bulb →
Turn Signal Front	7444NA LED or 7440NA	Buy 7444NA LED or 7440NA →
Turn Signal Rear	LED Bulb	Buy LED Bulb →
License Plate	2825	Buy 2825 →
Parking Light	2825 or 7444NA	Buy 2825 or 7444NA →
Reverse Light	921	Buy 921 →
Trunk Light	175	Buy 175 →

Installation Guide

Open in YouTube →

Video suggestion: Installation GuideBy YouTube

Other ATS Years

2019 2018 2017 2016 2014

More from Cadillac

Allante Brougham CT6 CTS Catera DTS DeVille Deville

Other Vehicles That Use HID-D3S LED Bulbs

2023 Chevrolet Camaro 2022 Dodge Charger 2022 Dodge Durango 2022 Hyundai Ioniq 2022 Kia Sportage 2021 Dodge Challenger