56 Electrical parts are listed for the 2021 Audi A4, in 6 part types, covering both the 2.0L L4 ELECTRIC/GAS Turbocharged and the 2.0L L4 Turbocharged. Each one has a brand, a manufacturer part number and notes that say where it fits.
The electrical system on the 2021 Audi A4 covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors. The largest groups are Battery (39 parts), Lighting Control Module (LCM) (5 parts) and Parking Aid Sensor (5 parts). The other 3 part types cover the remaining 7 parts.
The 2021 Audi A4 was sold with both the 2.0L L4 ELECTRIC/GAS Turbocharged and the 2.0L L4 Turbocharged. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Audi A4 electrical parts are ACDELCO (7 parts), DEKA (5 parts) and FVP (5 parts), plus 16 more brands. Quality grades include AGM, Performance AGM and Remanufactured.
9 parts on this 2021 Audi A4 page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including DEKA 9A48 (Battery) and VEMO V10730668 (Lighting Control Module (LCM)). Click any part number to see every vehicle that part fits.
Alternator / Generator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WAI GLOBAL Fits: 2.0L L4 Turbocharged | 39015N | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A4 Quattro | 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.
One part is listed for the 2021 Audi A4 — WAI GLOBAL 39015N.
Battery
AGM (Extended Life)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DEKA Popular Fits: 2.0L L4 Turbocharged | 9A48 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Popular Fits: 2.0L L4 Turbocharged | 9A94R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| FVP Popular Fits: 2.0L L4 Turbocharged | P94RAGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 94R | View on Amazon |
| LUCAS Popular Fits: 2.0L L4 Turbocharged | LBAGM004A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 48AGM | View on Amazon |
| LUCAS Popular Fits: 2.0L L4 Turbocharged | LBAGM001A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 47AGM | View on Amazon |
| LUCAS Popular Fits: 2.0L L4 Turbocharged | LBAGM005A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 94RAGM | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 48AGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 48 | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 94RAGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 48AGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 94RAGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 94R | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 49AGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 49 | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 49AGMHR | 🇺🇸 US 🇨🇦 CA | High ReserveAGM | View on Amazon |
| ACDELCO Fits: 2.0L L4 Turbocharged | 95RAGM | 🇺🇸 US 🇨🇦 CA | AGMBCI Group: 95R | View on Amazon |
| BOSCH Fits: 2.0L L4 Turbocharged | S6587B | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | AGMAGM | View on Amazon |
| BOSCH Fits: 2.0L L4 Turbocharged | S6588B | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | AGMAGM | View on Amazon |
| DEKA Fits: 2.0L L4 Turbocharged | 9A47 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Fits: 2.0L L4 Turbocharged | 9A49 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| DEKA Fits: 2.0L L4 Turbocharged | 9A95R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| EXIDE Fits: 2.0L L4 Turbocharged | MXH5L247 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 47 (H5) | View on Amazon |
| EXIDE Fits: 2.0L L4 Turbocharged | MXH6L348 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 48 (H6) | View on Amazon |
| EXIDE Fits: 2.0L L4 Turbocharged | MXH7L494R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 94R (H7) | View on Amazon |
| EXIDE Fits: 2.0L L4 Turbocharged | MXH8L549 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 49 (H8) | View on Amazon |
| EXIDE Fits: 2.0L L4 Turbocharged | MXH9L695R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Marathon MaxBCI Group 95R (H9) | View on Amazon |
| FVP Fits: 2.0L L4 Turbocharged | P47AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 47 | View on Amazon |
| FVP Fits: 2.0L L4 Turbocharged | P49AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 49 | View on Amazon |
| FVP Fits: 2.0L L4 Turbocharged | P48AGM | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Platinum AGMBCI Group: 48 | View on Amazon |
| LUCAS Fits: 2.0L L4 Turbocharged | LBAGM006A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 49AGM | View on Amazon |
| LUCAS Fits: 2.0L L4 Turbocharged | LBAGM007A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group: 95RAGM | View on Amazon |
| MOTORCRAFT Fits: 2.0L L4 Turbocharged | BAGM49H8 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Tested Tough AGMBCI Group: 49/H8 or BCI Group 49 | View on Amazon |
| MOTORCRAFT Fits: 2.0L L4 Turbocharged | BAGM95RH9 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Tested Tough AGMBCI Group 95R or BCI Group: 95R/H9 | View on Amazon |
| P1MAX Fits: 2.0L L4 Turbocharged | PMAGMH547 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 47 AGM680 CCA | View on Amazon |
| P1MAX Fits: 2.0L L4 Turbocharged | PMAGMH648 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 48 AGM760 CCA | View on Amazon |
| P1MAX Fits: 2.0L L4 Turbocharged | PMAGMH794R | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 94R AGM800 CCA | View on Amazon |
| P1MAX Fits: 2.0L L4 Turbocharged | PMAGMH849 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BCI Group 49 AGM850 CCA | View on Amazon |
| P1MAX Fits: 2.0L L4 Turbocharged | 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: 2.0L L4 Turbocharged | 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: 2.0L L4 Turbocharged | 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: 2.0L L4 Turbocharged | 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: 2.0L L4 Turbocharged | 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.
39 Battery parts for the 2021 Audi A4 come from 9 brands — ACDELCO, DEKA, LUCAS and 6 other brands. The "Popular" part is DEKA 9A48. They are grouped as AGM (Extended Life) and Performance AGM (Extended Life + Increased Power), with AGM (Extended Life) the largest group at 35 parts from ACDELCO, DEKA, LUCAS and 5 other brands.
Battery Current Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: 2.0L L4 Turbocharged | 5S16132 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A4 Quattro | 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 A4 — WELLS 5S16132.
Lighting Control Module (LCM)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO Popular Fits: 2.0L L4 Turbocharged | V10730668 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | To 03/10/2022 | View on Amazon |
| MARELLI Fits: 2.0L L4 Turbocharged | LRE539 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: 2.0L L4 Turbocharged | LRE309 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: 2.0L L4 Turbocharged | LRE310 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | LED | View on Amazon |
| MARELLI Fits: 2.0L L4 Turbocharged | 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 A4, from MARELLI and VEMO. VEMO V10730668 carries the "Popular" badge.
This group includes VEMO V10730668, MARELLI LRE539 and MARELLI LRE309 and the remaining parts above.
Parking Aid Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Popular Fits: 2.0L L4 Turbocharged | PPS120 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Black | View on Amazon |
| HELLA Fits: 2.0L L4 Turbocharged | 358141711 | 🇺🇸 US | 3-Pin ConnectorPlugged | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.0L L4 Turbocharged | PPS112 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Black | View on Amazon |
| VARIOUS MFR Fits: 2.0L L4 Turbocharged | AU1075104 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Customer Paints to Match | View on Amazon |
| VARIOUS MFR Fits: 2.0L L4 Turbocharged | 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.
5 Parking Aid Sensor parts are listed for the 2021 Audi A4, from STANDARD MOTOR PRODUCTS, VARIOUS MFR and HELLA. STANDARD MOTOR PRODUCTS PPS120 carries the "Popular" badge.
This group includes STANDARD MOTOR PRODUCTS PPS120, HELLA 358141711 and STANDARD MOTOR PRODUCTS PPS112 and the remaining parts above.
Starter Motor
New
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WAI GLOBAL Fits: 2.0L L4 Turbocharged | 31089N | 🇺🇸 US 🇨🇦 CA | View on Amazon |
Remanufactured
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PURE ENERGY Popular Fits: 2.0L L4 Turbocharged | 18256 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| FVP Fits: 2.0L L4 Turbocharged | 18256 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| REMY Fits: 2.0L L4 Turbocharged | 16409 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Remanufactured | View on Amazon |
| TERREPOWER Fits: 2.0L L4 Turbocharged | 52184 | 🇺🇸 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 A4, from WAI GLOBAL, PURE ENERGY, FVP and 2 other brands. PURE ENERGY 18256 carries the "Popular" badge.
In the New grade, WAI GLOBAL supplies 1 part: brand-new units rather than rebuilt ones. A representative part number is WAI GLOBAL 31089N.
In the Remanufactured grade, PURE ENERGY, FVP, REMY and 1 other brand supply 4 parts: factory-rebuilt units with new wear components. A representative part number is PURE ENERGY 18256.
Part numbers include PURE ENERGY 18256 and WAI GLOBAL 31089N, among others listed above.
Buying Electrical Parts for a 2021 Audi A4
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. Every electrical part here is 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 Lighting Control Module (LCM) .
Frequently Asked Questions
How many electrical parts fit the 2021 Audi A4?
Our catalog currently lists 56 electrical parts for the 2021 Audi A4 across 6 subcategories and 19 brands, covering both the 2.0L L4 ELECTRIC/GAS Turbocharged and the 2.0L L4 Turbocharged. Each part is matched to the engine(s) it fits.
Do electrical parts differ between 2021 Audi A4 engines?
Yes. Every electrical part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. 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 A4?
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 A4 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 A4?
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 A4
Electrical Parts for Other Audi A4 Years
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