The 2021 BMW 540I has 12 electrical switch & relay parts with verified fitment on this page — 4 part types and 9 brands, covering the 3.0L L6 Turbocharged engine. Each part includes a manufacturer part number and application notes.
On the 2021 BMW 540I, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. 11 parts of the 12 listed are Brake Light Switch (5 parts), A/C Refrigerant Pressure Switch (3 parts) and Oil Pressure Sender / Switch (3 parts). The other 1 part type covers the remaining 1 part.
The 2021 BMW 540I came with a single engine, the 3.0L L6 Turbocharged, and every part is verified against it.
9 brands supply electrical switch & relay parts for the 2021 BMW 540I, led by VEMO (2 parts), STANDARD MOTOR PRODUCTS (2 parts) and WELLS (2 parts), plus 6 more brands. Quality grades include Standard Replacement and Economy.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 BMW 540I. 1 part has it: STANDARD MOTOR PRODUCTS SLS541 (Brake Light Switch). Each part number opens a page with every vehicle that part fits.
A/C Refrigerant Pressure Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FOUR SEASONS | 20997 | 🇺🇸 US 🇨🇦 CA | Pressure Switch | View on Amazon |
| REIN | ACS0243P | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| UAC | SW11170C | 🇺🇸 US 🇨🇦 CA | 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 are listed for the 2021 BMW 540I, from FOUR SEASONS, REIN and UAC.
Listed part numbers: FOUR SEASONS 20997, REIN ACS0243P and UAC SW11170C.
Brake Light Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN | 920458 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| VEMO | V20730151 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Popular | SLS541 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| BECK/ARNLEY | 2012711 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| WELLS | 1S12667 | 🇺🇸 US 🇨🇦 CA | 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.
5 Brake Light Switch parts are listed for the 2021 BMW 540I, from DORMAN, VEMO, STANDARD MOTOR PRODUCTS and 2 other brands. STANDARD MOTOR PRODUCTS SLS541 carries the "Popular" badge.
In the Economy grade, DORMAN and VEMO supply 2 parts: the catalog's value-priced group. A representative part number is DORMAN 920458.
The Standard Replacement section lists 3 options from STANDARD MOTOR PRODUCTS, BECK/ARNLEY and WELLS — built to original-equipment specification. STANDARD MOTOR PRODUCTS SLS541 is listed in this group.
This group includes STANDARD MOTOR PRODUCTS SLS541, DORMAN 920458 and VEMO V20730151 and the remaining parts above.
Oil Pressure Sender / Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD | 1816559 | 🇺🇸 US 🇨🇦 CA | with Light | View on Amazon |
| STANDARD MOTOR PRODUCTS | PS754 | 🇺🇸 US | 540i Base Model | View on Amazon |
| WELLS | 1S16103 | 🇺🇸 US 🇨🇦 CA | 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.
3 Oil Pressure Sender / Switch parts are listed for the 2021 BMW 540I, from GPD, STANDARD MOTOR PRODUCTS and WELLS.
This group includes GPD 1816559, STANDARD MOTOR PRODUCTS PS754 and WELLS 1S16103.
Trunk Lid / Tailgate Release Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO | V20730310 | 🇺🇸 US 🇨🇦 CA | 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.
This group shows a single part: VEMO V20730310.
Buying Electrical Switch & Relay Parts for a 2021 BMW 540I
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 3.0L L6 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: Brake Light Switch and A/C Refrigerant Pressure Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2021 BMW 540I?
Our catalog currently lists 12 electrical switch & relay parts for the 2021 BMW 540I across 4 subcategories and 9 brands, covering the 3.0L L6 Turbocharged engine. Each part is matched to the engine(s) it fits.
What are the signs of electrical switch & relay problems on a 2021 BMW 540I?
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 BMW 540I 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 BMW 540I?
Every part on this page is matched to the 3.0L L6 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 BMW 540I
Electrical Switch & Relay Parts for Other BMW 540I 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.