BMW Electrical Sensors, Switches, & Relays

Transform your N54-powered BMW with the Turner Motorsport B58 Ignition Coil Conversion Kit—the ultimate solution for ignition system reliability and performance. Designed to eliminate the notorious misfires and power loss caused by factory OE pencil-style ignition coils, this kit is a game-changer for stock and modified vehicles alike. Whether you're chasing more power or improved drivability, the B58 ignition coils deliver up to 2.3x more spark energy, unleashing the full potential of your engine.

Why upgrade? The answer is simple: B58 ignition coils outperform all other ignition upgrades on the market with unparalleled spark energy and reliability. Ideal for high-performance builds or daily drivers, this kit eliminates common ignition problems while supporting increased power demands from software tunes like MHD or BM3. Plus, with the included plug-and-play wiring harness and proprietary boots, installation is seamless—no cutting or splicing is required.

Features:

Up to 2.3x More Spark Energy: Maximizes overall performance, offering sufficient output for heavily modified engines.
Plug-and-Play Installation: Includes custom brackets, wiring harnesses, and boots designed for factory mounting locations—no modifications needed.
DME Compatibility: Compatible with factory engine management software for hassle-free integration.
Rugged Durability: Bolt-on brackets are precision-machined from 6061-T6 aluminum with a sleek black anodized finish for a premium look and long-lasting performance.
Proprietary Design: Boots feature a built-in 1k OHM resistor to prevent electrical contact failures commonly seen in other kits.
Kit Contents:

(6) Turner Motorsport B Series Ignition Coils for N554/N55
(6) Turner Motorsport B58 Ignition Coil Conversion Wiring Harnesses
(6) Turner Motorsport B58 Ignition Coil Conversion Brackets
Optional Kit Selections:

Spark Plugs:
Bosch ZGR6STE2 (OEM)
NGK 97968 (One Step Colder)
NGK 97506 (Two Steps Colder)
Spark Plug Socket:
Schwaben 14mm 12pt Magnetic Socket
Schwaben 14mm 12pt Swivel Socket
Turner Motorsport offers a comprehensive installation guide, including detailed removal instructions and high-resolution images.

Transform your N55-powered BMW with the Turner Motorsport B58 Ignition Coil Conversion Kit—the ultimate solution for ignition system reliability and performance. Designed to eliminate the notorious misfires and power loss caused by factory OE pencil-style ignition coils, this kit is a game-changer for stock and modified vehicles alike. Whether you're chasing more power or improved drivability, the B58 ignition coils deliver up to 2.3x more spark energy, unleashing the full potential of your engine.

Why upgrade? The answer is simple: B58 ignition coils outperform all other ignition upgrades on the market with unparalleled spark energy and reliability. Ideal for high-performance builds or daily drivers, this kit eliminates common ignition problems while supporting increased power demands from software tunes like MHD or BM3. Plus, with the included plug-and-play wiring harness and proprietary boots, installation is seamless—no cutting or splicing is required.

Features:

Up to 2.3x More Spark Energy: Maximizes overall performance, offering sufficient output for heavily modified engines. Plug-and-Play Installation: Includes custom brackets, wiring harnesses, and boots designed for factory mounting locations—no modifications needed. DME Compatibility: Compatible with factory engine management software for hassle-free integration. Rugged Durability: Bolt-on brackets are precision-machined from 6061-T6 aluminum with a sleek black anodized finish for a premium look and long-lasting performance. Proprietary Design: Boots feature a built-in 1k OHM resistor to prevent electrical contact failures commonly seen in other kits. Kit Contents:

(6) Turner Motorsport B Series Ignition Coils for N554/N55 (6) Turner Motorsport B58 Ignition Coil Conversion Wiring Adapters (3) Turner Motorsport B58 Ignition Coil Conversion Brackets Optional Kit Selections:

Spark Plugs: Bosch ZGR6STE2 (OEM) NGK 97506 (One Step Colder) Spark Plug Socket: Schwaben 14mm 12pt Magnetic Socket Schwaben 14mm 12pt Swivel Socket Turner Motorsport offers a comprehensive installation guide, including detailed removal instructions and high-resolution images.

Say goodbye to misfires and hello to unparalleled ignition performance with the Turner Motorsport B58 Ignition Coil Conversion Kit. Designed with precision and engineered for reliability, it’s the ultimate upgrade for your N55-powered BMW!

If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E90 335d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.

If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E70 X5 35d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.

A replacement Bosch alternator for the 2001-2006 M3. Bosch is an original equipment supplier to BMW, and is the finest and most recognized German brand of alternator available. The Original BMW alternator sells for over double! Buy only the best alternator for your BMW -- buy a Bosch alternator. This is an OEM replacement for BMW part # 12317831436.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

A $80.00 refundable core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge. 

This item fits the following BMWs:
2001-2006 E46 BMW M3, M3 Convertible
2001-2002 Z3 BMW M Roadster M Coupe

If your car has died on the side of the road from a dead battery and you notice flickering or low powered headlights, it's likely your alternator failing. To be sure you are getting a high-quality part with a long life-span, choose this OEM Bosch Alternator. This is a brand new OEM replacement for BMW part # 12317501690.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high-performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts. All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

Knock sensors detect pings in the engine and adjust ignition timing to restore perfect operation. Faulty knock sensors will throw engine codes or even lead to engine damage. Replace your sensor with a reliable, high quality Bosch sensor to ensure proper engine ignition timing.

Bosch # 12141741648 OEM replacement for BMW part # 12141741648.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely s  eupplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

Fits the following vehicles:
1996-09/1999 E39 BMW 540i
1995-09/1999 E38 BMW 740i 740iL
1990-1999 E31 BMW 840Ci

Knock sensors detect pings in the engine and adjust ignition timing to restore perfect operation. Faulty knock sensors will throw engine codes or even lead to engine damage. Replace your sensor with a reliable, high quality Bosch sensor to ensure proper engine ignition timing.

Bosch # 13627568421 OEM replacement for BMW part # 13627568421, 12141709317, and 12141435502.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

If your car has died on the side of the road from a dead battery and you notice flickering or low powered head lights, it's likely your alternator failing. To be sure you are getting a high quality part with a long life-span, choose this OEM Bosch Alternator. This is an OEM replacement for BMW part # 12311407440.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

A refundable $70.00 core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge.

This item fits the following BMWs: 
1999-2003 E39 BMW M5 
 

If your headlights or interior are flickering or dimming while driving, there is a good chance your alternator is dying. This high quality Bosch replacement will have your electrical system back in top shape. OEM replacement for 12311744567 and 12311738352.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

A $80.00 refundable core charge is applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge. 

120 amp Bosch alternator for many BMW M62 V8's with 7 Poly Groove Pulley. Bosch is an original equipment supplier to BMW, and is the finest and most recognized German brand of alternator available. Buy only the best alternator for your BMW -- buy a Bosch alternator. Can be used in place of bmw part number. 12311433266

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.

A refundable core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge.

This Bosch Alternator fits the following BMWs:
1997-1998 E39 5 Series 540i
1997-1998 E38 BMW 740i 740il
1996-1999 E31 BMW 840i 840ci

Includes $65.00 core charge to be refunded on return of your rebuildable core.

Ensure optimal engine performance in your Mini with this Bosch oxygen sensor. Designed to replace a malfunctioning sensor, this unit measures the amount of unburned fuel in the exhaust pipe, allowing for adjustments to fuel mapping for reduced emissions and improved fuel economy.

• Restores engine performance and mileage
• Easy installation for quick restoration of vehicle performance
• Prevents sensor seizing with anti-seize application
• Regular maintenance helps prevent gradual sensor failure
• OEM supplier Bosch ensures quality and compatibility with Mini vehicles

Upgrade your Mini's engine efficiency and reduce emissions with this high-quality Bosch oxygen sensor.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.​

This genuine Bosch Starter fits the following BMWs:
1984-1985 E30 3 Series 323i 325e 325es
1982-12/1986 E28 5 Series 528e
1977-1983E21 3 Series 320/6 323i

Includes $45.00 core charge to be refunded on return of your rebuildable core.