This page lists 63 electrical parts for the 2021 Audi S4, across 6 part types, covering both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. Every part shows its brand, manufacturer part number and fitment notes.
On the 2021 Audi S4, the electrical system covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors. 53 parts of the 63 listed are Battery (40 parts), Parking Aid Sensor (8 parts) and Lighting Control Module (LCM) (5 parts). The other 3 part types cover the remaining 10 parts.
The 2021 Audi S4 was sold with both the 3.0L V6 Supercharged and the 3.0L V6 Turbocharged. 58 parts fit every engine; the other 5 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Audi S4 electrical parts are ACDELCO (8 parts), FVP (6 parts) and DEKA (5 parts), plus 17 more brands. Quality grades include AGM, Remanufactured and Performance AGM.
10 parts on this 2021 Audi S4 page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including ACDELCO 47AGM (Battery) and VEMO V10730668 (Lighting Control Module (LCM)). Click any part number to see every vehicle that part fits.
Alternator / Generator
New
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALEO Fits: all 2021 S4 engines | 443008 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pulley Diameter 58mm110 Amps | View on Amazon |
| WAI GLOBAL Fits: all 2021 S4 engines | 21089N | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Valeo 150 Amp | View on Amazon |
Remanufactured
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FVP Fits: all 2021 S4 engines | 10470 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| PURE ENERGY Fits: all 2021 S4 engines | 10470 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
This table covers the alternators that charge the battery and run the electrical load. Typical signs include dim lights at idle, a battery lamp, or a growl from the charging pulley. Load-test the battery and inspect the belt and grounds — a bad ground mimics a failed alternator.
4 Alternator / Generator parts are listed for the 2021 Audi S4, from VALEO, WAI GLOBAL, FVP and 1 other brand. All of them fit every engine offered in the 2021 S4.
In the New grade, VALEO and WAI GLOBAL supply 2 parts: brand-new units rather than rebuilt ones. A representative part number is VALEO 443008.
In the Remanufactured grade, FVP and PURE ENERGY supply 2 parts: factory-rebuilt units with new wear components. A representative part number is FVP 10470.
Listed part numbers: VALEO 443008, WAI GLOBAL 21089N and FVP 10470, plus the other parts above.
Battery
AGM (Extended Life)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Popular Fits: all 2021 S4 engines | 47AGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 47 | View on Amazon |
| DEKA Popular Fits: all 2021 S4 engines | 9A48 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Popular Fits: all 2021 S4 engines | 9A94R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| FVP Popular Fits: all 2021 S4 engines | P94RAGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 94R | View on Amazon |
| LUCAS Popular Fits: all 2021 S4 engines | LBAGM004A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 48AGM | View on Amazon |
| LUCAS Popular Fits: all 2021 S4 engines | LBAGM001A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 47AGM | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 48AGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 48 | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 47SAGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 47 | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 94RAGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 48AGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 94RAGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 94R | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 49AGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 49 | View on Amazon |
| ACDELCO Fits: all 2021 S4 engines | 49AGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| BOSCH Fits: all 2021 S4 engines | S6587B | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | AGMAGM | View on Amazon |
| BOSCH Fits: all 2021 S4 engines | S6588B | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | AGMAGM | View on Amazon |
| DEKA Fits: all 2021 S4 engines | 9A47 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Fits: all 2021 S4 engines | 9A49 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Fits: all 2021 S4 engines | 9A95R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| EXIDE Fits: all 2021 S4 engines | MXH5L247 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 47 (H5) | View on Amazon |
| EXIDE Fits: all 2021 S4 engines | MXH6L348 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 48 (H6) | View on Amazon |
| EXIDE Fits: all 2021 S4 engines | MXH7L494R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 94R (H7) | View on Amazon |
| EXIDE Fits: all 2021 S4 engines | MXH8L549 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 49 (H8) | View on Amazon |
| EXIDE Fits: all 2021 S4 engines | MXH9L695R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 95R (H9) | View on Amazon |
| FVP Fits: all 2021 S4 engines | P47AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 47 | View on Amazon |
| FVP Fits: all 2021 S4 engines | P49AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 49 | View on Amazon |
| FVP Fits: all 2021 S4 engines | P48AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 48 | View on Amazon |
| LUCAS Fits: all 2021 S4 engines | LBAGM005A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 94RAGM | View on Amazon |
| LUCAS Fits: all 2021 S4 engines | LBAGM006A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 49AGM | View on Amazon |
| LUCAS Fits: all 2021 S4 engines | LBAGM007A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 95RAGM | View on Amazon |
| MOTORCRAFT Fits: all 2021 S4 engines | BAGM49H8 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Tested Tough AGMBCI Group: 49/H8 or BCI Group 49 | View on Amazon |
| MOTORCRAFT Fits: all 2021 S4 engines | BAGM95RH9 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Tested Tough AGMBCI Group 95R or BCI Group: 95R/H9 | View on Amazon |
| P1MAX Fits: all 2021 S4 engines | PMAGMH547 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 47 AGM680 CCA | View on Amazon |
| P1MAX Fits: all 2021 S4 engines | PMAGMH648 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 48 AGM760 CCA | View on Amazon |
| P1MAX Fits: all 2021 S4 engines | PMAGMH794R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 94R AGM800 CCA | View on Amazon |
| P1MAX Fits: all 2021 S4 engines | PMAGMH849 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 49 AGM850 CCA | View on Amazon |
| P1MAX Fits: all 2021 S4 engines | PMAGMH995R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 95R AGM950 CCA | View on Amazon |
Performance AGM (Extended Life + Increased Power)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FULLRIVER Fits: all 2021 S4 engines | FT61047 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 47(Length X Width X Height) 9.49 In x 6.89 In x 7.48 In | View on Amazon |
| FULLRIVER Fits: all 2021 S4 engines | FT68048 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 48(Length X Width X Height) 10.94 In x 6.89 In x 7.48 In | View on Amazon |
| FULLRIVER Fits: all 2021 S4 engines | FT85094R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 94R(Length X Width X Height) 12.36 In x 6.85 In x 7.48 In | View on Amazon |
| FULLRIVER Fits: all 2021 S4 engines | FT89049 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 49(Length X Width X Height) 13.9 In x 6.89 In x 7.48 In | View on Amazon |
This table covers the batteries listed by group size and specification. Typical signs include slow cranking, a battery lamp, or a no-start after the vehicle sat overnight. Confirm group size and terminal layout in the notes. Clean the posts and the ground before condemning the battery.
40 Battery parts for the 2021 Audi S4 come from 9 brands — ACDELCO, DEKA, LUCAS and 6 other brands. The "Popular" part is ACDELCO 47AGM. Grades run from AGM (Extended Life) through Performance AGM (Extended Life + Increased Power); AGM (Extended Life) is the most populated section, led by ACDELCO, DEKA, LUCAS and 5 other brands.
Battery Current Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Fits: 3.0L V6 Turbocharged | 358158001 | 🇺🇸 US | BoltedIntelligent Battery Sensor | View on Amazon |
This table covers the Battery Current sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors.
One part is listed for the 2021 Audi S4 — HELLA 358158001.
Lighting Control Module (LCM)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO Popular Fits: all 2021 S4 engines | V10730668 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | To 03/10/2022 | View on Amazon |
| MARELLI Fits: all 2021 S4 engines | LRE539 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: all 2021 S4 engines | LRE309 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: all 2021 S4 engines | LRE310 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: all 2021 S4 engines | LRE538 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
This table covers the modules that control the exterior lighting.
5 Lighting Control Module (LCM) parts are listed for the 2021 Audi S4, from MARELLI and VEMO. VEMO V10730668 carries the "Popular" badge. All of them fit every engine offered in the 2021 S4.
Part numbers include VEMO V10730668, MARELLI LRE539 and MARELLI LRE309, among others listed above.
Parking Aid Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Popular Fits: all 2021 S4 engines | PPS120 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Black | View on Amazon |
| STANDARD MOTOR PRODUCTS Popular Fits: all 2021 S4 engines | PPS112 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Black | View on Amazon |
| HELLA Fits: 3.0L V6 Turbocharged | 358141711 | 🇺🇸 US | 3-Pin ConnectorPlugged | View on Amazon |
| MARELLI Fits: 3.0L V6 Supercharged | SDP107 | 🇲🇽 MX | Rear | View on Amazon |
| TECHPRO Fits: 3.0L V6 Supercharged | AU1075103 | 🇲🇽 MX | Customer Paints to Match | View on Amazon |
| TECHPRO Fits: 3.0L V6 Supercharged | AU1075104 | 🇲🇽 MX | Customer Paints to Match | View on Amazon |
| VARIOUS MFR Fits: all 2021 S4 engines | AU1075104 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Customer Paints to Match | View on Amazon |
| VARIOUS MFR Fits: all 2021 S4 engines | AU1075103 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Customer Paints to Match | View on Amazon |
This table covers the ultrasonic park-aid sensors in the bumper. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors.
8 Parking Aid Sensor parts are listed for the 2021 Audi S4, from STANDARD MOTOR PRODUCTS, TECHPRO, VARIOUS MFR and 2 other brands. STANDARD MOTOR PRODUCTS PPS120 carries the "Popular" badge. 4 parts fit every engine; the other 4 are engine-specific.
Listed part numbers: STANDARD MOTOR PRODUCTS PPS120, STANDARD MOTOR PRODUCTS PPS112 and HELLA 358141711, plus the other parts above.
Starter Motor
New
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WAI GLOBAL Popular Fits: all 2021 S4 engines | 33286N | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
Remanufactured
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FVP Fits: all 2021 S4 engines | 19631 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| PURE ENERGY Fits: all 2021 S4 engines | 19631 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| REMY Fits: all 2021 S4 engines | 16411 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| TERREPOWER Fits: all 2021 S4 engines | 52185 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
This table covers the starter motors that crank the engine. Typical signs include no motion, a squeal, or a motor that only runs on one speed. Confirm power, ground and the control module before replacing the motor.
5 Starter Motor parts are listed for the 2021 Audi S4, from WAI GLOBAL, FVP, PURE ENERGY and 2 other brands. WAI GLOBAL 33286N carries the "Popular" badge. All of them fit every engine offered in the 2021 S4.
New: 1 part, from WAI GLOBAL. A representative part number is WAI GLOBAL 33286N.
Remanufactured: 4 parts, from FVP, PURE ENERGY, REMY and 1 other brand. A representative part number is FVP 19631.
Listed part numbers: WAI GLOBAL 33286N and FVP 19631, plus the other parts above.
Buying Electrical Parts for a 2021 Audi S4
On this vehicle, the electrical system covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors.
- Match the engine first. Some electrical parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, clean or renew the battery terminals and grounds with any charging-system repair.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Battery and Parking Aid Sensor .
Frequently Asked Questions
How many electrical parts fit the 2021 Audi S4?
Our catalog currently lists 63 electrical parts for the 2021 Audi S4 across 6 subcategories and 20 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 parts differ between 2021 Audi S4 engines?
Some do. 58 parts fit every engine; the other 5 are engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of electrical problems on a 2021 Audi S4?
Common symptoms include slow cranking on cold mornings, a battery light that flickers, dim lights at idle, or a check-engine code pointing at a sensor circuit. 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, clean or renew the battery terminals and grounds with any charging-system repair.
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?
First match the engine — each row shows which engine(s) the part fits. Then test before replacing — a failed alternator and a bad ground can look identical, and sensors are frequently condemned for wiring faults. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Audi S4
Electrical Parts for Other Audi S4 Years
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