BMW Electrical Sensors, Switches, & Relays for BMW E46 M3 S54 (1999-2005)

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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.

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ECS Heavy Duty Ground Cable Upgrade (12421737755) - E30, E36, E39, E4...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:49996974
Part#: 059235LA01
In Stock
New Item
Sale - Save 20% $ 29.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.99 USD
Free Shipping
Sale - Save 20%
$ 29.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.99 USD
Free Shipping

If you're experiencing hard starting, flaky charging, or other electrical issues, your engine ground strap may be the culprit. On older BMWs, the engine ground strap is a thin, non-insulated cable that spans from the engine mount arm to the frame horn. Despite the seemingly simple nature of this part, on older cars, it is known to cause massive headaches. Due to its non-insulated design, years of exposure to water, dirt, and road salt will cause the wire to corrode, ultimately leading to complete failure. A break in this cable will cause an open circuit, resulting in issues with the vehicle's electrical system and potentially leading to a no-start condition.

To solve this issue, ECS has engineered an exact-fit, upgraded ground strap for your BMW! Unlike its OEM counterpart, this design features insulated, large-gauge copper wire for dependable conductivity and long-lasting durability. Additionally, factory-style lugs are zinc-coated, crimped, and soldered, ensuring protection against corrosion and oxidation.

Whether you're replacing a visibly corroded strap or proactively preventing failure, this solution from ECS is sure to provide lasting performance and protection.

FEATURES

Direct-fit replacement and upgrade for E30 (318i/is), E36, E39, E46, and others Solves intermittent grounding issues caused by aging OEM straps Clean, stealthy design that fits seamlessly in factory engine bays Factory length and lug orientation for drop-in fitment 2 AWG tinned copper cable for excellent conductivity and corrosion resistance Zinc-coated lugs, crimped and soldered to resist moisture and oxidation Black UL1015-grade insulation withstands oil, heat, and abrasion Discreet ECS label for a clean, OEM+ look Replaces OEM part numbers 12421737755 and 12421714262.

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Mishimoto Ignition Coil, 8-Pack - BMW N63 & S63 Engines
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:51075067
Part#: MMIG-BMW-1108
Ships in 3 Business Days
New Item
$ 274.99 USD
Free Shipping on orders $49 and up
The Mishimoto Ignition Coil (MMIC-BMW-11B) focuses on durability and electrical precision.
Battery Tender Plus Advanced Battery Charging System
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Battery Tender - Corporate Logo
T#:49892371
Part#: BTT0210128
Back Ordered
New Item
$ 69.99 USD
Free Shipping on orders $49 and up

Mishimoto Ignition Coil - Single - BMW M54, N20, N52, N54, N55, N62, ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:51075090
Part#: MMIG-BMW-02
Ships in 3 Business Days
New Item
$ 72.99 USD
Free Shipping on orders $49 and up
The Mishimoto BMW Ignition Coil is built to handle the intense heat cycles found in BMW’s modern turbocharged and naturally aspirated engines.

Wire Pinning Kit - MLK 1.2 Female Jack
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Genuine BMW - Corporate Logo
T#:55281746
Part#: 125275WRKT
Ships in 7 Business Days
New Item
$ 37.40 USD
Free Shipping on orders $49 and up
This Genuine BMW wiring repair kit is the ideal solution to refresh worn-out terminal connections in your Ultimate Driving Machine.
Morimoto Standalone Can-Bus Wiring Harness - H4 / 9003 - Priced Each ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Morimoto - Corporate Logo
T#:54388428
Part#: H240
Ships on Jul 20, 2026
New Item
Sale - Save 17% $ 21.99

This product was last offered at the strikethrough price on
06-23-2026

$ 18.21 USD
Free Shipping on orders $49 and up
Sale - Save 17%
$ 21.99

This product was last offered at the strikethrough price on
06-23-2026

$ 18.21 USD
Free Shipping on orders $49 and up

Meyle Exhaust Camshaft Position Sensor - BMW S54 S62
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Meyle - Corporate Logo
T#:55497462
Part#: 3148000038
Special Order: No Guaranteed ETA
New Item
$ 26.99 USD
$ 26.99 USD
Don't let a failing camshaft position sensor rob your vehicle of power or cut your track day short. This Meyle replacement camshaft sensor is built to deliver fast, highly accurate data to the ECU, preventing the performance drops, sluggish throttle response, and rough idling caused by worn-out factory electronics. Engineered to withstand high underhood heat and intense vibrations, it keeps your ignition timing and fuel delivery tightly synced, whether you are daily driving or pushing through high-RPM pulls.
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