This page lists 10 electrical switch & relay parts for the 2021 BMW M4, across 6 part types, covering the 3.0L L6 Turbocharged engine. Every part shows its brand, manufacturer part number and fitment notes.
On the 2021 BMW M4, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. Most of the listed parts are A/C Refrigerant Pressure Switch (3 parts), Oil Pressure Sender / Switch (3 parts) and Clutch Pedal Position / Starter Safety Switch (1 part). The other 3 part types cover the remaining 3 parts.
Every part on this page is matched to the 3.0L L6 Turbocharged — the only engine offered in the 2021 BMW M4.
The most listed brands for 2021 BMW M4 electrical switch & relay parts are WELLS (4 parts), FOUR SEASONS (1 part) and REIN (1 part), plus 4 more brands.
Each part number listed for the 2021 BMW M4 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 for the 2021 BMW M4 come from 3 brands — FOUR SEASONS, REIN and UAC.
This group includes FOUR SEASONS 20997, REIN ACS0243P and UAC SW11170C.
Clutch Pedal Position / Starter Safety Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY | 2012717 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the Clutch Pedal Position / Starter Safety 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 BMW M4 — BECK/ARNLEY 2012717.
Headlamp Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1S18204 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the column or dash switches that control the exterior 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.
One part is listed for the 2021 BMW M4 — WELLS 1S18204.
Ignition Starter Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1S16683 | 🇺🇸 US 🇨🇦 CA | with 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.
One part is listed for the 2021 BMW M4 — WELLS 1S16683.
Oil Pressure Sender / Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD | 1816559 | 🇺🇸 US 🇨🇦 CA | with Light | View on Amazon |
| STANDARD MOTOR PRODUCTS | PS529 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| WELLS | 1S11835 | 🇺🇸 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 for the 2021 BMW M4 come from 3 brands — GPD, STANDARD MOTOR PRODUCTS and WELLS.
Listed part numbers: GPD 1816559, STANDARD MOTOR PRODUCTS PS529 and WELLS 1S11835.
Turn Signal Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS | 1S17939 | 🇺🇸 US 🇨🇦 CA | 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: WELLS 1S17939.
Buying Electrical Switch & Relay Parts for a 2021 BMW M4
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: A/C Refrigerant Pressure Switch and Oil Pressure Sender / Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2021 BMW M4?
Our catalog currently lists 10 electrical switch & relay parts for the 2021 BMW M4 across 6 subcategories and 7 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 M4?
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 M4 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 M4?
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 M4
Electrical Switch & Relay Parts for Other BMW M4 Years
Switch vehicle or jump to a subcategory
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.