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ECS BMW Electrical Sensors, Switches, & Relays

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...
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ECS - Corporate Logo
T#:49996974
Part#: 059235LA01
Ships in 4 Business Days
New Item
Sale - Save 23% $ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 23.19 USD
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Sale - Save 23%
$ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 23.19 USD
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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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ECS Heavy Duty Ground Cable Upgrade (12427549396) - E9X AWD
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:48642696
Part#: 059226LA02
In Stock
New Item
Sale - Save 44% $ 39.99

This product was last offered at the strikethrough price on
02-04-2026

$ 22.49 USD
Free Shipping
Sale - Save 44%
$ 39.99

This product was last offered at the strikethrough price on
02-04-2026

$ 22.49 USD
Free Shipping

If you're experiencing hard starting, flaky charging, or other electrical issues, your engine ground strap may be the culprit. On E9X BMWs, the engine ground strap is a thin, non-insulated cable that spans from the left 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 E9X 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 RWD E82/E88, E84, and E9X applications 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 number 12427549396.

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ECS Heavy Duty Ground Cable Upgrade (12427549393) - E9X, E82/E88, E84...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:48367010
Part#: 059226LA01
In Stock
New Item
Sale - Save 48% $ 39.99

This product was last offered at the strikethrough price on
02-04-2026

$ 20.99 USD
Free Shipping
Sale - Save 48%
$ 39.99

This product was last offered at the strikethrough price on
02-04-2026

$ 20.99 USD
Free Shipping

If you're experiencing hard starting, flaky charging, or other electrical issues, your engine ground strap may be the culprit. On E9X BMWs, the engine ground strap is a thin, non-insulated cable that spans from the left 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 E9X 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 RWD E82/E88, E84, and E9X applications 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 12427549393, 12427795404, and 12427790559.

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ECS Heavy Duty Ground Cable Upgrade (12427557027) - E70 X5, E71 X6 ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:49996976
Part#: 059261LA01
In Stock
New Item
Sale - Save 28% $ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 21.74 USD
Free Shipping
Sale - Save 28%
$ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 21.74 USD
Free Shipping

If you're experiencing hard starting, flaky charging, or other electrical issues, your engine ground strap may be the culprit. On E70/E71 BMWs, the engine ground strap is a thin, non-insulated cable that spans from the left 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 X5/X6! 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 E70 X5 and E71 X6 applications 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 number 12427557027.

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3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412930
Part#: 12521706096
In Stock
Sale - Save 11% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 9.78 USD
Free Shipping on orders $49 and up
Sale - Save 11%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 9.78 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the idle air control valve (IACV).

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# 12521706096 - Commonly used for the idle air control valve (IACV).

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

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3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412925
Part#: 12521433915
In Stock
Sale - Save 40% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.54 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.54 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

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3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412931
Part#: 12527519996
In Stock
Sale - Save 39% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.69 USD
Free Shipping on orders $49 and up
Sale - Save 39%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.69 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

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3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412947
Part#: 12521433916
In Stock
Sale - Save 44% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.17 USD
Free Shipping on orders $49 and up
Sale - Save 44%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.17 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

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LK-2M 2 Pin Connector Package
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ECS - Corporate Logo
T#:40072446
Part#: LK2M
In Stock
Sale - Save 20% $ 5.99

This product was last offered at the strikethrough price on
05-03-2026

$ 4.79 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 5.99

This product was last offered at the strikethrough price on
05-03-2026

$ 4.79 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

3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412918
Part#: 12521732596
In Stock
Sale - Save 39% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.69 USD
Free Shipping on orders $49 and up
Sale - Save 39%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 6.69 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# 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
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412924
Part#: 12521433917
In Stock
Sale - Save 47% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.83 USD
Free Shipping on orders $49 and up
Sale - Save 47%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.83 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

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2 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412928
Part#: 12521427615
Ships on Jul 27, 2026
Sale - Save 37% $ 7.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.01 USD
Free Shipping on orders $49 and up
Sale - Save 37%
$ 7.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.01 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
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2 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships on Jul 28, 2026
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.24 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