Cadillac STS Headlight Bulb Size
Find the correct headlight bulb size for your Cadillac STS. Covers low beam, high beam, fog lights, and turn signals for all years.
Last updated: 2026-05-07 • Reading time: 8 min • By AllOEMManuals Editorial Team
Quick Answer
The Cadillac STS headlight bulb size depends on the model year and trim. Common sizes include H11 (low beam), 9005/HB3 (high beam), and H16 (fog lights) — see the full breakdown below.
| Generation | Years | Top spec |
|---|---|---|
| 2006-2011 | 2006-2011 | H11 or H7 |
| 2005-2005 | 2005-2005 | 9006/HB4 or H4 |
Know the exact headlight bulb size job for your Cadillac STS
The Cadillac STS headlight bulb size depends on the model year and trim. Common sizes include H11 (low beam), 9005/HB3 (high beam), and H16 (fog lights) — see the full breakdown below.
Bulb size can change between reflector, projector, HID, LED, and market-specific housings. Once the spec is confirmed, use the supplies and purchase links below to build the full one-trip shopping list before you start the repair.
Exact Vehicle Check
Use the archive navigator when you need the exact engine, trim, or production-branch manual instead of a broad year-range summary. That keeps the buying list and repair steps aligned with the real vehicle.
2006-2011
Representative 2006 manual branch for 2006-2011
A L L Diagnostic Trouble Codes ( DTC )
STS AWD V6-3.6L VIN 7
A L L Diagnostic Trouble Codes ( DTC ) — 2006 Cadillac STS AWD V6-3.6L VIN 7 Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reimagined Home >> Cadillac >> 2006 >> STS A...
Open factory section →A L L Diagnostic Trouble Codes ( DTC )
STS AWD V8-4.6L VIN A
A L L Diagnostic Trouble Codes ( DTC ) — 2006 Cadillac STS AWD V8-4.6L VIN A Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reimagined Home >> Cadillac >> 2006 >> STS A...
Open factory section →2005-2005
Representative 2005 manual branch for 2005-2005
A L L Diagnostic Trouble Codes ( DTC )
STS V6-3.6L VIN 7
A L L Diagnostic Trouble Codes ( DTC ) — 2005 Cadillac STS V6-3.6L VIN 7 Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reimagined Home >> Cadillac >> 2005 >> STS V6-3....
Open factory section →A L L Diagnostic Trouble Codes ( DTC )
STS V8-4.6L VIN A
A L L Diagnostic Trouble Codes ( DTC ) — 2005 Cadillac STS V8-4.6L VIN A Service Manual ~ LEMON Manuals LEMON Manuals: Repair Knowledge Reimagined Home >> Cadillac >> 2005 >> STS V8-4....
Open factory section →2006-2011
2006-2011- →Never touch halogen bulbs with bare fingers — skin oil causes hot spots and premature failure
- →LED upgrade bulbs are available but may cause CANBUS errors on some models
- →Replace bulbs in pairs — if one side burned out, the other is likely near end of life
2005-2005
2005-2005- →Never touch halogen bulbs with bare fingers — skin oil causes hot spots and premature failure
- →Replace bulbs in pairs — if one side burned out, the other is likely near end of life
One-Trip Shopping List
Recommended supplies and tools for this job, grouped so you can buy everything before the repair starts.
LED Upgrade Bulbs
Brighter, whiter light for better nighttime visibility.
Replacement Halogens
Standard OEM-spec bulbs for reliable replacement.
Dielectric Grease
Protects electrical connectors from moisture.
Latex-Free Gloves
Avoid fingerprints on the bulb and keep glass clean.
Project Essentials
Basic tool sets, gloves, and cleaning supplies for your Cadillac STS so the job is ready when the parts arrive.
Frequently Asked Questions
- What size headlight bulb does a Cadillac STS use?
- The Cadillac STS headlight bulb size varies by year. Newer models often use factory LED units, while older models use H11, H7, or 9006 halogen bulbs. Check the year-specific specs below for your exact fitment.
- Can I put LED bulbs in my Cadillac STS?
- If your Cadillac STS has halogen headlights, you can install LED replacement bulbs. Look for bulbs with a proper beam pattern (projector-compatible) to avoid blinding other drivers. Some models may need anti-flicker adapters.
- How do I replace the headlight bulb on a Cadillac STS?
- On most Cadillac STS models, you can access the headlight bulb from behind the headlight assembly in the engine bay. Twist the bulb socket counterclockwise, pull out the old bulb, insert the new one (don't touch the glass), and twist back in.
- Why does my Cadillac STS headlight keep burning out?
- Frequent bulb burnout on the Cadillac STS is usually caused by a loose connection, moisture in the housing, touching the bulb glass during installation, or a voltage regulator issue. Check the connector and housing seal.
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Author & Review
Written by AllOEMManuals Editorial Team. Reviewed by ASE-certified technicians and updated with factory-reference checks for fitment-sensitive steps.
This guide was drafted with AI assistance and reviewed for accuracy by a human editor.
Last updated: 2026-05-07