What is the low beam headlight bulb size for a 2009 Cadillac STS?

The 2009 Cadillac STS uses a HID-D1S 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 2009 Cadillac STS?

The high beam bulb size for the 2009 Cadillac STS is 9005 LED.

Why are my 2009 Cadillac STS headlights dim?

Dim headlights on a 2009 Cadillac STS can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a HID-D1S LED LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2009 Cadillac STS fog light?

The 2009 Cadillac STS uses a H3 LED bulb for the fog light position.

Is the 2009 Cadillac STS single or dual beam?

The 2009 Cadillac STS uses a dual bulb headlight system. This means you have separate bulbs for high and low beams.

Can I install LED bulbs on my 2009 Cadillac STS?

Yes, the 2009 Cadillac STS comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a HID-D1S LED LED conversion kit for the low beams.

Does the 2009 Cadillac STS have fog lights?

Yes, the 2009 Cadillac STS takes a H3 LED bulb for the fog light position.

Did the 2009 Cadillac STS change headlight bulb sizes from the previous year?

No — the 2009 Cadillac STS uses the same bulb sizes as the 2008 model. This configuration has been consistent across the 2008–2009 generation.

Is the 2009 Cadillac STS the first or last year to use HID-D1S LED bulbs?

The 2009 Cadillac STS is the last year in the 2008–2009 generation to use the HID-D1S LED bulb for the low beam headlight.

How do I change the headlight on a 2009 Cadillac STS?

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-D1S 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 2009 Cadillac STS?

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-D1S 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 2009 Cadillac STS headlights?

A pair of HID HID-D1S 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 2009 Cadillac STS?

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-D1S LED position are available as direct plug-and-play replacements.

The 2009 Cadillac STS is the last model year to use this bulb configuration (2008–2009).

Fitment Guaranteed for 2009 Cadillac STS

What Size Bulbs Does a 2009 Cadillac STS 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 2009 Cadillac STS Have?

The 2009 Cadillac STS utilizes a refined lighting configuration featuring 14 distinct bulb positions. It features an extensive lighting system powered by premium factory HID/Xenon technology utilizing D1S projector housings for high-intensity output. This model belongs to the mid years of the STS's 2005-2011 production span.

Can You Put LED Bulbs in a 2009 Cadillac STS?

The 2009 Cadillac STS is already equipped with factory D1S 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 H3 LED fog lights are typically halogen and are excellent candidates for an LED upgrade to match the color temperature of your HID headlights.

2009 Cadillac STS Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	HID-D1S LED	Buy HID-D1S LED →
High Beam	9005 LED	Buy 9005 LED →
Fog Light	H3 LED	Buy H3 LED →
Brake Light	LED Bulb	Buy LED Bulb →
Side Marker	2825 LED	Buy 2825 LED →
Turn Signal Front	3757AK LED	Buy 3757AK LED →
Turn Signal Rear	LED Bulb	Buy LED Bulb →
Dome Light	212-2	Buy 212-2 →
License Plate	2825	Buy 2825 →
Map Light	PC175	Buy PC175 →
Parking Light	3757AK	Buy 3757AK →
Reverse Light	3157KX	Buy 3157KX →
Trunk Light	LED Light	Buy LED Light →
Daytime Running	3157CK	Buy 3157CK →

How do the 2009 Cadillac STS's bulbs compare to other years?

The 2009 Cadillac STS uses the same bulbs as the 2008 model.

The 2010 model switched to a different bulb configuration.

This bulb configuration covers the 2008–2009 model years. ← 2008 2010 →

Finding the best installation guide...

Other STS Years

2011 2010 2008 2007 2006 2005

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