The 2021 Audi A5 has 23 electrical switch & relay parts with verified fitment on this page — 13 part types and 9 brands, covering the 2.0L L4 Turbocharged engine. Each part includes a manufacturer part number and application notes.
The switch and relay system on the 2021 Audi A5 covers the switches, relays and flashers that route power to everything the driver touches. The largest groups are Oil Pressure Sender / Switch (7 parts), A/C Refrigerant Pressure Switch (3 parts) and Brake Light Switch (2 parts). The other 10 part types cover the remaining 11 parts.
Every part on this page is matched to the 2.0L L4 Turbocharged — the only engine offered in the 2021 Audi A5.
The most listed brands for 2021 Audi A5 electrical switch & relay parts are HELLA (6 parts), WELLS (5 parts) and VEMO (4 parts), plus 6 more brands. Quality grades include Standard Replacement and Economy.
2 parts on this 2021 Audi A5 page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including REIN ELP0078 (Oil Pressure Sender / Switch) and HELLA 009600281 (Oil Pressure Sender / Switch). Click any part number to see every vehicle that part fits.
A/C Condenser Fan Motor Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA | 933332451 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 4-pin connector | View on Amazon |
This table covers the relays that control the A/C Condenser Fan Motor circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
This group shows a single part: HELLA 933332451.
A/C Refrigerant Pressure Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FOUR SEASONS | 37427 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Switch | View on Amazon |
| UAC | SW11103C | 🇺🇸 US 🇨🇦 CA | Pressure Transducer | View on Amazon |
| UAC | SW11224C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Transducer | View on Amazon |
This table covers the pressure switches on the A/C circuit. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
3 A/C Refrigerant Pressure Switch parts for the 2021 Audi A5 come from 2 brands — UAC and FOUR SEASONS.
Listed part numbers: FOUR SEASONS 37427, UAC SW11103C and UAC SW11224C.
Accessory Power Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA | 933332451 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 4-pin connector | View on Amazon |
This table covers the relays that control the Accessory Power circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
One part is listed for the 2021 Audi A5 — HELLA 933332451.
Brake Light Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ÜRO PARTS | 5G0698459 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Sportback | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1S10862 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback | View on Amazon |
This table covers the pedal-mounted switch that turns on the brake lamps. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
2 Brake Light Switch parts for the 2021 Audi A5 come from 2 brands — ÜRO PARTS and WELLS.
The Economy section lists 1 option from ÜRO PARTS — the catalog's value-priced group. ÜRO PARTS 5G0698459 is listed in this group.
In the Standard Replacement grade, WELLS supplies 1 part: built to original-equipment specification. A representative part number is WELLS 1S10862.
Listed part numbers: ÜRO PARTS 5G0698459 and WELLS 1S10862.
Fog / Driving Lamp Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA | 933332451 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 4-pin connector | View on Amazon |
This table covers the relays that control the Fog / Driving Lamp circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
This group shows a single part: HELLA 933332451.
Fuel Pump / Circuit Opening Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA | 933332451 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 4-pin connector | View on Amazon |
This table covers the relays that control the Fuel Pump / Circuit Opening circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
This group shows a single part: HELLA 933332451.
Horn Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1R2303 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Mounting Hardware Included: No | View on Amazon |
This table covers the relays that control the Horn circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
One part is listed for the 2021 Audi A5 — WELLS 1R2303.
Multi-Function Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ÜRO PARTS | 7M0951253A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback | View on Amazon |
| WELLS | 1R1007 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Mounting Hardware Included: No | View on Amazon |
This table covers the relays that control the Multi-Function circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
2 Multi-Function Relay parts for the 2021 Audi A5 come from 2 brands — ÜRO PARTS and WELLS.
This group includes ÜRO PARTS 7M0951253A and WELLS 1R1007.
Oil Pressure Sender / Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| REIN Popular | ELP0078 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 SportbackBrown, with .55-.85 Bar | View on Amazon |
| WALKER PRODUCTS | 2561102 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Popular | 009600281 | 🇺🇸 US | 1-Pin ConnectorHousing Color: Green | View on Amazon |
| STANDARD MOTOR PRODUCTS | PS665 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BlackColor: Green | View on Amazon |
| VEMO | V10720420 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | From 08/28/2017To 07/31/2023 | View on Amazon |
| WELLS | 1S16087 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback0.3 - 0.6 Bar | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1S17518 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback0.55 - 0.85 Bar | View on Amazon |
This table covers the senders and switches that report oil pressure to the gauge or lamp. Typical signs include a lamp that stays on, or a gauge that never moves. Confirm power and ground at the connector before replacing the sender or switch.
7 Oil Pressure Sender / Switch parts for the 2021 Audi A5 come from 6 brands — WELLS, REIN, WALKER PRODUCTS and 3 other brands. The "Popular" part is REIN ELP0078.
The Economy section: 2 options from REIN and WALKER PRODUCTS. REIN ELP0078 is listed in this group.
Standard Replacement: 4 parts, from HELLA, STANDARD MOTOR PRODUCTS, VEMO and 1 other brand. A representative part number is HELLA 009600281.
1 further part sits outside the graded sections, with the same engine-level match.
Part numbers include REIN ELP0078, WALKER PRODUCTS 2561102 and HELLA 009600281, among others listed above.
Power Window Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO | V10730721 | 🇺🇸 US | Front LeftSwitch Panel Assembly | View on Amazon |
This table covers the switches that command each window motor. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
This group shows a single part: VEMO V10730721.
Radiator Fan Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA | 933332451 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 4-pin connector | View on Amazon |
This table covers the relays that control the Radiator Fan circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
One part is listed for the 2021 Audi A5 — HELLA 933332451.
Trunk Lid / Tailgate Release Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO | V10730458 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fits CoupeA5 Quattroor A5 Sportback | View on Amazon |
This table covers the Trunk Lid / Tailgate Release switches. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
One part is listed for the 2021 Audi A5 — VEMO V10730458.
Turn Signal Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO | V10800003 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | A5 Quattro or A5 Sportback | View on Amazon |
This table covers the combination / turn-signal switches. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
This group shows a single part: VEMO V10800003.
Buying Electrical Switch & Relay Parts for a 2021 Audi A5
On this vehicle, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches.
- Confirm you have the 2.0L L4 Turbocharged engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Oil Pressure Sender / Switch and A/C Refrigerant Pressure Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2021 Audi A5?
Our catalog currently lists 23 electrical switch & relay parts for the 2021 Audi A5 across 13 subcategories and 9 brands, covering the 2.0L L4 Turbocharged engine. Each part is matched to the engine(s) it fits.
What are the signs of electrical switch & relay problems on a 2021 Audi A5?
Common symptoms include accessories that work intermittently, a click without action, or one function dead while its fuse tests fine. 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, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
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 A5 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 A5?
Every part on this page is matched to the 2.0L L4 Turbocharged engine. Then swap a suspect relay with an identical known-good one from the fuse box before buying — it is the fastest diagnostic there is. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Audi A5
Electrical Switch & Relay Parts for Other Audi A5 Years
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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.