BMW Electrical Sensors, Switches, & Relays for BMW 3 Series E46 (1999-2005)

Clear BMW chassis

Please ensure your correct model is selected

Electrical gremlins can be very frustrating. Luckily your BMW's electrical system is better than most, even if it's 25 years old. Here you will find electrical relays, sensors, switches, and modules for the engine, camshaft, and crankshaft. Our parts are OEM, Genuine BMW, or approved aftermarket brands that we have an excellent track record with. There is no middle ground with electrical parts - it either works perfectly or not. And there's nothing more frustrating than a new part that fails right out of the box. So it's important to choose quality replacement parts over a cheap but faulty piece.

Sub-Categories

Sort By:

Braille - Corporate Logo
T#:558037
Part#: B14115
Ships in 5 Business Days
$ 204.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your cars operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind!
Show More Show Less
Braille - Corporate Logo
T#:558038
Part#: B2015
Ships in 8 Business Days
$ 237.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your cars operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind! The B2015 is Braille's most popular non-carbon racing battery and is able to start larger engines easily for racing and offers daily driving capability for most 4 and 6 cylinders engine vehicles. Physical Specifications: BCI Group: All sizes Weight: 15lbs / 6.8kg Length: 6.8" / 173mm Width: 3.4" / 86mm Height: 6.1" / 155mm Polarity: Right Side Positive Performance Specifications: Voltage: 12 Full Charge Voltage: 13.2 Pulse Cranking Amps (PCA): 1067 Amp Hour (AH): 21 Life Cycle @ 10% DOD: 3100 *THIS BATTERY REQUIRES A CUSTOM MOUNTING SOLUTION. The size and weight are significantly smaller than a stock battery and will not be held in place by the stock battery mount*
Show More Show Less
Braille - Corporate Logo
T#:558042
Part#: B3121
Ships in 6 Business Days
$ 270.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your car's operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind! The B3121 battery from Braille is their lightest do-everything battery available, offering 1380 pulse cranking amps that can crank over V8 engines with ease while still coming in at under 22 pounds, half of the weight of a standard Group 34 battery! This is thanks to their Advanced AGM racing technology that allows them to put a ton of power into a very small package. Physical Specifications: BCI Group: All sizes Weight: 21lbs / 9.5kg Length: 6.6" / 168mm Width: 5.2" / 132mm Height: 6.8" / 173mm Polarity: Right Side Positive Terminal Type: Steel terminal block with M6 bolt Performance Specifications: Voltage: 12v Recharge Voltage: 14.4V – 14.6V Maintenance charge voltage: 13.8V 5s Pulse Cranking Amps (PCA): 1380 10s PDC: 124 Amp Hour (Ah): 31 Watt Hour (Wh): 372 Life Cycle @ 10% DOD: 3100 Charging Temperature 0C to 50C Discharge Temperature range -40C to +60C Storage temperature -40C to +60C *THIS BATTERY REQUIRES A CUSTOM MOUNTING SOLUTION. The size and weight are significantly smaller than a stock battery and will not be held in place by the stock battery mount*
Show More Show Less

Braille Performance Intensity Carbon Lithium-ION Battery - i48CX - 10...
This item is classified as Hazardous Materials and requires special shipping and handling. We cannot ship this item out of the US or with priority shi
Braille - Corporate Logo
T#:558047
Part#: I48CX
Ships in 5 Business Days
$ 1,164.99 USD
Free Shipping on orders $49 and up
The ultra-lightweight, standard height I48CX lithium-ION battery from Braille Battery is a popular choice among BMW enthusiasts looking for a drop-in replacement battery that shaves off a ton of weight, 35 pounds in total! Thanks to the Group 48 design of this battery, no modifications are needed for installation. This is perfect for anyone looking to drive their car both on and off of the track, without any negative side effects, and wants a battery with a 10-15 year life span!
Show More Show Less

Braille - Corporate Logo
T#:558046
Part#: G30
Ships in 6 Business Days
$ 522.99 USD
Free Shipping on orders $49 and up
The G30 lithium battery from Braille is designed for the Import Tuner market (4 and 6 cylinder) for track use and has enough power for small black V8 race cars and hot rods with light electrical demands/accessories and standard compression. The G30 comes in the popular ETX 30 Group size, just like the B3121 AGM, so it is small and light enough to mount in a variety of locations. Incorporated in this battery is the same technology used in their race winning batteries used by nearly every OEM developer in classes ranging from SCCA to Formula 1.
Show More Show Less
LK-2M 2 Pin Connector Package
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:40072446
Part#: LK2M
In Stock
Sale - Save 34% $ 6.99

This product was last offered at the strikethrough price on
11-07-2026

$ 4.61 USD
Free Shipping on orders $49 and up
Sale - Save 34%
$ 6.99

This product was last offered at the strikethrough price on
11-07-2026

$ 4.61 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the engine oil pressure switch.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less

Oil Pressure Switch (fits most BMWs)
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:363
Part#: 12617568480
In Stock
$ 7.99

This product was last offered at the strikethrough price on
07-07-2026

$ 5.39 USD
Free Shipping on orders $49 and up
$ 5.39 USD
Free Shipping on orders $49 and up
Having your oil pressure light come on can mean very serious problems. Or it could just be this switch that fails several times over a car's lifespan. By no means should you ignore the warning light but replacing this sensor could be the actual culprit. The other problem with this switch is that oil can leak past its seal. With the oil under a lot of pressure at this point, the oil loss can be a serious concern. It's a simple replacement when doing most oil change work.

This Oil Pressure Switch fits the following BMWs:
1985-1991 E30 318i, 318is, 325e, 325i, M3
1992-1999 E36 318i/is, 325i/is, 328i/is, 323is, M3
1992-1997 E31 840i, 850i
1988-1994 E32 735i, 735iL, 740i, 740iL
1989-1995 E34 525i, 530i, 535i, 540i, M5
1995-2001 E38 740i, 740iL, 750i, 750iL
1996-2002 Z3 Roadster/Coupe 1.9, 2.3, 2.5, 2.8, 3.0, 3.2
1997-2003 E39 525i, 528i, 530i, 540i, M5
1999-2005 E46 323, 325, 328, 330, M3
2000-2003 Z8 roadster
2001-2006 E53 X5 X5 3.0i, X5 4.4i, X5 4.6is, X5 4.8is
2002+ E65/E66 745i, 745li, 750i, 750li, 760i, B7 Alpina
2003+ Z4 Roadster/Coupe Z4 2.5, 3.0, 3.0si
2004+ E60 525i, 530i, 535i, 545i, 550i, M5
2005+ E63/E64 645Ci, 650i, M6
2005+ E83 X3 X3 2.5, X3 3.0
2006+ E90/E92 325, 328, 330, 335
2007+ E70 X5 X5 3.0i, X5 4.8i
Show More Show Less
3 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412931
Part#: 12527519996
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the pencil-style ignition coil connector.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12527519996 - Commonly used for the pencil-style ignition coil connector.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less

3 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412918
Part#: 12521732596
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the camshaft position sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521732596 - Commonly used for the camshaft position sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less

3 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412947
Part#: 12521433916
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the crankshaft position sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521433916 - Commonly used for the crankshaft position sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less
3 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412924
Part#: 12521433917
Ships on Jan 27, 2027
Sale - Save 14% $ 8.99

This product was last offered at the strikethrough price on
10-28-2026

$ 7.69 USD
Free Shipping on orders $49 and up
Sale - Save 14%
$ 8.99

This product was last offered at the strikethrough price on
10-28-2026

$ 7.69 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the camshaft position sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521433917 - Commonly used for the camshaft position sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less
3 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412925
Part#: 12521433915
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the engine oil level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521433915 - Commonly used for the engine oil level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less


Liqui-Moly Battery Clamp Grease - 50 grams
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
We Price Match - Give Us A Call or Chat!
Liqui-Moly - Corporate Logo
T#:1195997
Part#: 20244
In Stock
30% off MSRP $ 7.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 5.59 USD
Free Shipping on orders $49 and up
30% off MSRP
$ 7.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 5.59 USD
Free Shipping on orders $49 and up
Excellent corrosion protection for your battery and other connections
SEG Automotive - Corporate Logo
T#:54851984
Part#: 12317541694
Ships in 1 Business Day
New Item
$ 521.99

This product was last offered at the strikethrough price on
07-16-2026

$ 470.99 USD
Free Shipping on orders $49 and up
$ 470.99 USD
Free Shipping on orders $49 and up
SEG Automotive - Corporate Logo
T#:54851980
Part#: 12317519618
Ships on Dec 7, 2026
New Item
$ 503.99

This product was last offered at the strikethrough price on
07-16-2026

$ 500.99 USD
Free Shipping on orders $49 and up
$ 500.99 USD
Free Shipping on orders $49 and up

SEG Automotive - Corporate Logo
T#:58965212
Part#: 0124.525.561
Ships on Dec 7, 2026
New Item
$ 487.99 USD
Free Shipping on orders $49 and up
SEG Automotive, the company behind Bosch's starter motor and generator business, builds this brand-new 150-amp alternator with a freewheel pulley that smooths out belt loads for a quieter, longer-lasting accessory drive.
Show More Show Less

SEG Automotive - Corporate Logo
T#:58965210
Part#: 0124.515.052
Ships on Dec 7, 2026
New Item
$ 485.99 USD
Free Shipping on orders $49 and up
A strong charging system keeps everything from your ignition to your stereo working at its best, and a failing alternator can undermine all of it.
SEG Automotive - Corporate Logo
T#:58965213
Part#: 0124.525.523
Ships on Dec 7, 2026
New Item
$ 495.99 USD
Free Shipping on orders $49 and up
Your BMW's charging system powers everything from ignition to infotainment, so a weak alternator affects the whole car.

2 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412928
Part#: 12521427615
In Stock
Sale - Save 35% $ 7.99

This product was last offered at the strikethrough price on
11-07-2026

$ 5.19 USD
Free Shipping on orders $49 and up
Sale - Save 35%
$ 7.99

This product was last offered at the strikethrough price on
11-07-2026

$ 5.19 USD
Free Shipping on orders $49 and up
Includes connector housing with terminals and seals. Commonly used for the engine oil pressure switch. ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need. Each connector includes an additional terminal in case one becomes lost or damaged during installation. *OEM cross reference PN# 12521427615 - Commonly used for the engine oil pressure switch. Please reference the original part number from the existing connector to confirm fitment, before ordering. Suggested tools: Suggested crimping pliers: T#387193 Wire De-pin tools: 12pc De-Pin Tool Set - T#386379 23pc De-Pin Tool Set - T#641943
Show More Show Less
2 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes 10X Entries For Our Spin To Win Sweepstakes!
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
11-07-2026

$ 6.59 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the coolant level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 61132359999 - Commonly used for the coolant level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less