8 Electrical bulb & socket parts are listed for the 2021 Audi S4, in 6 part types, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Each one has a brand, a manufacturer part number and notes that say where it fits.
On the 2021 Audi S4, the bulb and socket system covers every bulb and socket on the vehicle, from headlamps to instrument-cluster illumination. Most of the listed parts are Headlamp Bulb (2 parts), Turn Signal Lamp Bulb (2 parts) and Brake Light Bulb (1 part). The other 3 part types cover the remaining 3 parts.
The 2021 Audi S4 was sold with both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. All 8 parts on this page fit every engine.
The most listed brands for 2021 Audi S4 electrical bulb & socket parts are PHILIPS (7 parts) and WAGNER (1 part). Quality grades include Standard Replacement, Extended Life and HID.
Each part number listed for the 2021 Audi S4 opens a page with every vehicle that part fits.
Brake Light Bulb
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | 1156RLED | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | VisionLED | View on Amazon |
This table covers the bulbs in the stop lamps. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
One part is listed for the 2021 Audi S4 — PHILIPS 1156RLED.
Fog / Driving Lamp Bulb
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | H21W | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the bulbs in the fog and driving lamps. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
This group shows a single part: PHILIPS H21W.
Glove Box Light Bulb
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | 12256 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the bulbs in the glove-box lamp. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
This group shows a single part: PHILIPS 12256.
Headlamp Bulb
HID (intense white light)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WAGNER Fits: all 2021 S4 engines | D5S | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | High Beam and Low BeamHid Type | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | H8 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | High Beam | View on Amazon |
This table covers the bulbs that light the headlamps. Typical signs include a dark lamp, a flicker over bumps, or a bulb that keeps failing on one side. Avoid touching a halogen capsule. Repeated failure in one socket is usually the socket or ground, not the bulb.
2 Headlamp Bulb parts for the 2021 Audi S4 come from 2 brands — WAGNER and PHILIPS. Every part fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged.
In the HID (intense white light) grade, WAGNER supplies 1 part: grouped under the catalog's "HID (intense white light)" designation — the notes column spells out what sets them apart. A representative part number is WAGNER D5S.
In the Standard Replacement grade, PHILIPS supplies 1 part: built to original-equipment specification. A representative part number is PHILIPS H8.
Part numbers include WAGNER D5S and PHILIPS H8.
Tail Lamp Bulb
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | 1156RLED | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | VisionLED | View on Amazon |
This table covers the bulbs in the tail lamps. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
This group shows a single part: PHILIPS 1156RLED.
Turn Signal Lamp Bulb
Extended Life
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | PY21WLL | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Longer LifeNatural Amber | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: all 2021 S4 engines | 12174NA | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Natural Amber | View on Amazon |
This table covers the bulbs in the turn-signal lamps. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
PHILIPS supplies both parts for the 2021 Audi S4. All of them fit every engine offered in the 2021 S4.
The Extended Life section lists 1 option from PHILIPS — grouped under the catalog's "Extended Life" designation — the notes column spells out what sets them apart. PHILIPS PY21WLL is listed in this group.
The Standard Replacement section: 1 option from PHILIPS. PHILIPS 12174NA is listed in this group.
Listed part numbers: PHILIPS PY21WLL and PHILIPS 12174NA.
Buying Electrical Bulb & Socket Parts for a 2021 Audi S4
On this vehicle, the bulb and socket system covers every bulb and socket on the vehicle, from headlamps to instrument-cluster illumination.
- You do not need to pick an engine: every electrical bulb & socket part on this page fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace bulbs in pairs so both sides age together, and put a smear of dielectric grease on the new socket contacts.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Headlamp Bulb and Turn Signal Lamp Bulb .
Frequently Asked Questions
How many electrical bulb & socket parts fit the 2021 Audi S4?
Our catalog currently lists 8 electrical bulb & socket parts for the 2021 Audi S4 across 6 subcategories and 2 brands, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Each part is matched to the engine(s) it fits.
Do electrical bulb & socket parts differ between 2021 Audi S4 engines?
No. On this page every electrical bulb & socket part fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. You do not need to pick an engine to choose the right row — use the notes for position and trim.
What are the signs of electrical bulb & socket problems on a 2021 Audi S4?
Common symptoms include a lamp that flickers over bumps, melted or discolored socket plastic, or bulbs that keep failing early on one side. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace bulbs in pairs so both sides age together, and put a smear of dielectric grease on the new socket contacts.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Audi S4 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Audi S4?
Every part on this page already fits both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Then repeated bulb failure in one position usually means a socket or ground problem, not bad bulbs — replace the socket rather than chase it. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Audi S4
Electrical Bulb & Socket Parts for Other Audi S4 Years
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