BMW Electrical Sensors, Switches, & Relays for BMW 5 Series E39 (1996-2003)

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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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Turner Alpha-N IAT Sensor Relocation Kit - S54 S62 S85
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Turner Motorsport - Corporate Logo
T#:597496
Part#: 014579TMSKT
In Stock
Sale - Save 35% $ 130.96
$ 85.12 USD
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Sale - Save 35% $ 130.96
$ 85.12 USD
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Turner Plug-and-Play IAT Relocation Kit
For vehicles with production date from 09/1998
10X Entries For Our Spin To Win Sweepstakes!
Turner Motorsport - Corporate Logo
T#:391751
Part#: 014579TMS
In Stock
Sale - Save 28% $ 201.99
Starting at $ 145.57 USD
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Sale - Save 28% $ 201.99
Starting at $ 145.57 USD
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All vehicles will lose some degree of performance due to heat soak under the right operating conditions.  Engine management systems constantly monitor operating conditions and modifying parameters based on sensor inputs. BMW integrated the intake air temp sensor in the MAF housing on models such as the E39 M5, and, being sandwiched behind a hot radiator and in some applications next to an even hotter valve cover, this is less than ideal for performance applications. Absorbing excess heat from its surroundings, the MAF can’t shed it fast enough, and the ECU reads an inaccurately high intake air temperature. Compensating for this false hot air measurement, the ECU pulls timing and runs a richer fuel mixture, resulting in a significant loss of torque.

What can you do?  Locate an intake air temp sensor in a location where it can properly measure incoming air temps and where it's less prone to heat soak. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly.  The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard. 

The Turner engineering team was initially skeptical of the claimed performance benefits of this modification. They first set out validate the functionality and performance benefit of a temp sensor relocation. Replicating stop-and-go traffic heat soak in a 2001 540i was a simple task in a controlled environment - their dynometer. First the car was heat soaked to simulate being stuck in traffic or moving at low speeds by running the car four times on the dyno with the dyno's cooling fans disabled. The fans were then turned on for three more runs to observe the recovery rate once air flow was reintroduced. The test: following this procedure once with a stock IAT, and once with their relocation kit in place. 

The result? Turner recovered 11lb-ft torque at 2500rpm through use of their relocation kit, with even greater recovery to be found for M5 owners. Here are the heat soak-related torque losses Turner experienced:

Stock IAT location:
18rwtq at 2500rpm
10rwtq at 3000rpm
9rwtq at 3700rpm

Turner IAT Relocation:
7rwtq at 2500rpm
5rwtq at 3000rpm
5rwtq at 3700rpm

**Click here for installation instructions**

The Turner engineering team designed a complete plug and play kit (unlike all other options on the market) that makes for quick, easy, and reversible installation. Weather-sealed connectors keep out the elements, while sheathed wiring offers a clean appearance underhood. With a harness nearly 3 feet long - the Turner IAT relocation kit offers flexibility in positioning, but not too long that you're left with unsightly excess wiring. Turner recommends positioning the sensor in a location away from engine heat, but still within the intake ducting to achieve accurate intake temp readings - such as the far side of the base of the airbox. Vehicles with cold air intakes with cone-style filters can even position the sensor in the end of the filter. Simply drill a hole in your (cool) location of choice and plug in the harness. More information including installation instructions and some good examples of sensor mounting locations can be found in our DIY PDF. 

We include everything you need to relocate your IAT, just select your desired sensor brand below - Genuine BMW or original equipment Beru.

Also the perfect plug-n-play option for anyone looking to upgrade their intake to utilize an Alpha-N tune!

Note for vehicles with M62 engine: applicable to 1999 and up

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Turner Plug-And-Play Alpha-N IAT Sensor Relocation Kit
10X Entries For Our Spin To Win Sweepstakes!
Turner Motorsport - Corporate Logo
T#:638071
Part#: 014579TMSKT1
In Stock
Sale - Save 40% $ 142.99
$ 85.79 USD
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Sale - Save 40% $ 142.99
$ 85.79 USD
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What can you do to get rid of this heat soak? Turner designed an IAT relocation kit that moves the intake air temp sensor to a cooler location. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly. The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard.
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Turner Motorsport Oil Temperature Sensor Flange
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Turner Motorsport - Corporate Logo
T#:359474
Part#: TEN9990001
In Stock
Sale - Save 57% $ 100.99
$ 42.99 USD
Limited Qty Sale
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Sale - Save 57% $ 100.99
$ 42.99 USD
Limited Qty Sale
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The Turner Motorsport Oil Temperature Sensor Flange was designed to get your oil temperature from the best possible location: the sump. Most of the factory and aftermarket sensors are located after the oil pump, which does not give you an accurate temp reading of the oil that is actually lubricating the engine. At the factory temp sensor location the sensor picks up heat not only from the oil stream, but also from the oil pump and housing which will skew the reading. Other aftermarket adapters can be give inaccurate readings from their location and/or design limitations. And may require making unnecessary modifications. By relocating the sensor to the oil sump it reduces clutter and sits flush against the bottom of the oil pan to avoid potential clearance issues. Testing that we have done on and off the track shows that the sump location is the most accurate. We accomplish this by removing the factory oil level sensor or block off plate and using the existing hole and bolt pattern on the oil pan with no additional modifications. Any sensor with an M12 x 1.50mm thread can be used in the flange. 

Note that removing the factory oil level sensor will trigger the low oil fault/warning light. There's no elegant way around this but since the Temp Flange is considered a race-only part we assume you will be checking your own oil level anyway or be using a stand-alone dash/engine management system that does not track oil level. And having the most accurate oil temp is more important.

Applications:
1987-1991 E30 M3
1992-1999 3 Series E36 M3 3.0 and M3 3.2 Euro Models Only!
1999-2006 3 Series E46 All
1991-1995 5 Series E34 525i M50
1997-2003 5 Series E39 525i, 528i, 530i, 540i, 540iP, M5
2004-xxxx 5 Series E60 525i, 530i
1995-2001 7 Series E38 
Z3 2.5, 2.5i, 2.8, 3.0i, M3.2 S54
Z4 2.5, 3.0
Z8 All

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Bavarian Autosport - Corporate Logo
T#:639841
Part#: 12141703221
Ships Sep 24, 2025
Sale - Save 25% $ 36.99
$ 27.74 USD
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Sale - Save 25% $ 36.99
$ 27.74 USD
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Faulty camshaft sensors can lead to a number of issues such as hard starts, stalling at low speeds, and check engine (SES) lights. Restore your BMW's smooth operation and reliability by replacing it with a high-quality camshaft sensor from Bav Auto! From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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Bav Auto Camshaft Position Sensor - E38 740i 740iL 750iL
For vehicles with production date up to 09/1998
Bavarian Autosport - Corporate Logo
T#:639840
Part#: 12141742185
Ships Sep 24, 2025
Sale - Save 10% $ 64.99
$ 58.49 USD
Free Shipping on orders $49 and up
Sale - Save 10% $ 64.99
$ 58.49 USD
Free Shipping on orders $49 and up
Faulty camshaft sensors can lead to a number of issues such as hard starts, stalling at low speeds, and check engine (SES) lights. Restore your BMW's smooth operation and reliability by replacing it with a high-quality camshaft sensor from Bav Auto! From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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Bavarian Autosport - Corporate Logo
T#:25042543
Part#: 12317501690
In Stock
Sale - Save 10% $ 206.99
$ 186.29 USD
Free Shipping on orders $49 and up
Sale - Save 10% $ 206.99
$ 186.29 USD
Free Shipping on orders $49 and up
Bavarian Autosport - Corporate Logo
T#:639833
Part#: 13621433076
Ships on Jul 31, 2025
Sale - Save 15% $ 16.99
$ 14.44 USD
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Sale - Save 15% $ 16.99
$ 14.44 USD
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This is the coolant temperature sensor used in many BMW models from the late-1990s to the mid-2010s. The engine computer relies on the coolant temp to set the fuel mapping for the engine. As the car warms up the computer changes the fuel mixture. If your car is running a bit rich (too much fuel) it could be because this sensor is failing and not sending the correct info to the computer. This sensor is located in a variety of places depending on the engine. But it's one of those easy replacement items 'while you're in there' when doing a water pump or thermostat replacement. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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