35 Electrical switch & relay parts are listed for the 2021 Audi TT, in 11 part types, covering both the 2.0L L4 Turbocharged and the 2.5L L5 Turbocharged. Each one has a brand, a manufacturer part number and notes that say where it fits.
On the 2021 Audi TT, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. 25 parts of the 35 listed are Oil Pressure Sender / Switch (21 parts), A/C Refrigerant Pressure Switch (2 parts) and Horn Relay (2 parts). The other 8 part types cover the remaining 10 parts.
The 2021 Audi TT was sold with both the 2.0L L4 Turbocharged and the 2.5L L5 Turbocharged. 12 parts fit every engine; the other 23 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Audi TT electrical switch & relay parts are HELLA (10 parts), WELLS (8 parts) and WALKER PRODUCTS (3 parts), plus 11 more brands. Quality grades include Standard Replacement and Economy.
4 parts on this 2021 Audi TT 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 BECK/ARNLEY 2011754 (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 Fits: all 2021 TT engines | 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 Fits: all 2021 TT engines | 37427 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Switch | View on Amazon |
| UAC Fits: all 2021 TT engines | 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.
2 A/C Refrigerant Pressure Switch parts for the 2021 Audi TT come from 2 brands — FOUR SEASONS and UAC. Every part fits both the 2.0L L4 Turbocharged and the 2.5L L5 Turbocharged.
Listed part numbers: FOUR SEASONS 37427 and UAC SW11224C.
Accessory Power Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Fits: all 2021 TT engines | 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 TT — HELLA 933332451.
Brake Light Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: all 2021 TT engines | 1S10862 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 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.
This group shows a single part: WELLS 1S10862.
Fog / Driving Lamp Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Fits: all 2021 TT engines | 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 Fits: all 2021 TT engines | 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 |
|---|---|---|---|---|
| HELLA Fits: all 2021 TT engines | 965453801 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 5-pin connector | View on Amazon |
| WELLS Fits: 2.0L L4 Turbocharged | 1R2303 | 🇺🇸 US 🇨🇦 CA | 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.
2 Horn Relay parts are listed for the 2021 Audi TT, from HELLA and WELLS. 1 part fits every engine; the other 1 is engine-specific.
Part numbers include HELLA 965453801 and WELLS 1R2303.
Ignition Starter Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO Fits: 2.0L L4 Turbocharged | V15803346 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| WELLS Fits: all 2021 TT engines | 1S17907 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | TTS Quattrowith Push Button Switch | View on Amazon |
This table covers the ignition switches that feed the starter 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.
2 Ignition Starter Switch parts are listed for the 2021 Audi TT, from VEMO and WELLS. 1 part fits every engine; the other 1 is engine-specific.
Listed part numbers: VEMO V15803346 and WELLS 1S17907.
Multi-Function Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ÜRO PARTS Fits: all 2021 TT engines | 7M0951253A | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| WELLS Fits: all 2021 TT engines | 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 TT come from 2 brands — ÜRO PARTS and WELLS. Every part fits both the 2.0L L4 Turbocharged and the 2.5L L5 Turbocharged.
This group includes ÜRO PARTS 7M0951253A and WELLS 1R1007.
Oil Pressure Sender / Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| REIN Popular Fits: 2.0L L4 Turbocharged | ELP0078 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Brown, with .55-.85 Bar | View on Amazon |
| WALKER PRODUCTS Fits: 2.0L L4 Turbocharged | 2561061 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Brown | View on Amazon |
| WALKER PRODUCTS Fits: 2.0L L4 Turbocharged | 2561033 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 2.15-2.95 Barblue | View on Amazon |
| WALKER PRODUCTS Fits: 2.0L L4 Turbocharged | 2561102 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 0.30-0.60 BARGreen | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY Popular Fits: 2.0L L4 Turbocharged | 2011754 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Light0.55-0.85 BAR | View on Amazon |
| HELLA Popular Fits: 2.0L L4 Turbocharged | 008280001 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 1-Pin ConnectorColor: Green or Brown | View on Amazon |
| HELLA Popular Fits: 2.0L L4 Turbocharged | 008280031 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 1-Pin ConnectorColor: Brown | View on Amazon |
| BECK/ARNLEY Fits: 2.0L L4 Turbocharged | 2011983 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Light2.15-2.95 BAR | View on Amazon |
| HELLA Fits: 2.0L L4 Turbocharged | 009600241 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 1-Pin ConnectorColor: Black or Color: Blue | View on Amazon |
| HELLA Fits: 2.0L L4 Turbocharged | 009600281 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 1-Pin ConnectorHousing Color: Green | View on Amazon |
| ROSTRA Fits: 2.0L L4 Turbocharged | 501269 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Brown Connector | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.0L L4 Turbocharged | PS489 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Terminal Quantity: 2 | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.0L L4 Turbocharged | PS665 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | BlackColor: Green | View on Amazon |
| WELLS Fits: 2.0L L4 Turbocharged | 1S16087 | 🇺🇸 US 🇨🇦 CA | TT Quattro0.3 - 0.6 Bar | View on Amazon |
| WELLS Fits: 2.0L L4 Turbocharged | 1S12101 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fits TTS Quattroor TT Quattro2.15 - 2.95 Bar | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FACET Fits: 2.5L L5 Turbocharged | 250053 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| GPD Fits: 2.5L L5 Turbocharged | 1816565 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| HOLSTEIN Fits: 2.0L L4 Turbocharged | 2OPS0303 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Dark Blue1 Blade Terminal | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L5 Turbocharged | PS778 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Connector Type: Plug InFinish: Metal, Plastic | View on Amazon |
| WELLS Fits: 2.0L L4 Turbocharged | 1S17518 | 🇺🇸 US 🇨🇦 CA | TT Quattro0.55 - 0.85 Bar | View on Amazon |
| WELLS Fits: 2.5L L5 Turbocharged | 1S16084 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 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.
21 Oil Pressure Sender / Switch parts for the 2021 Audi TT come from 10 brands — HELLA, WELLS, WALKER PRODUCTS and 7 other brands. The "Popular" part is REIN ELP0078.
The Economy section lists 4 options from WALKER PRODUCTS and REIN — the catalog's value-priced group. REIN ELP0078 is listed in this group.
In the Standard Replacement grade, HELLA, BECK/ARNLEY, STANDARD MOTOR PRODUCTS and 2 other brands supply 11 parts: built to original-equipment specification. A representative part number is BECK/ARNLEY 2011754.
6 further parts sit outside the graded sections, with the same engine-level match.
Radiator Fan Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Fits: all 2021 TT engines | 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 TT — HELLA 933332451.
Buying Electrical Switch & Relay Parts for a 2021 Audi TT
On this vehicle, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches.
- Match the engine first. Some electrical switch & relay 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, 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 TT?
Our catalog currently lists 35 electrical switch & relay parts for the 2021 Audi TT across 11 subcategories and 14 brands, covering both the 2.0L L4 Turbocharged and the 2.5L L5 Turbocharged. Each part is matched to the engine(s) it fits.
Do electrical switch & relay parts differ between 2021 Audi TT engines?
Some do. 12 parts fit every engine; the other 23 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 switch & relay problems on a 2021 Audi TT?
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 TT 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 TT?
First match the engine — each row shows which engine(s) the part fits. 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 TT
Electrical Switch & Relay Parts for Other Audi TT Years
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