For every vehicle an automobile manufacturer sells there is a specific electronic control unit (ECU) which belongs to that car.

The item you seek may have different part numbers within the same make/model/year. Within a particular model there can also be multiple options available.

For example, let's look at the popular BMW X3 Sports Utility Vehicle.

In 2015 consumers had the option of either the X3 sDrive28i, X3 xDrive28i, X3 xDrive28d or X3 xDrive35i.

Different emission standards, engines, transmissions and drive trains are variables among the different makes within the same class of vehicle which make it difficult to determine the correct ECM for your car without a part number. 

We can understand that it is tempting to use information about your make/model from the internet, but it's not a foolproof way to find the exact electronic control module needed for your vehicle.

The best way to ensure your car is compatible with one of our ECU tuners - is to have the exact part number from the defective/original unit in your automobile.

Most units that you pull from your vehicle will have a white sticker on them with the part number and multiple identifier numbers which can make it unclear when trying to locate the part number for your ECU.

Below are examples of ECU stickers...

(As you can see it's not always clear which number is the ECU part number. A red arrow indicates which number is the ECU part number for each sticker.)

     1)  37820-P0A-A51 is an ECM for a Honda Accord
     2)  F7UF-12A650-AFB is an ECM for a Ford Van 
     3)  MD163156 is an ECM for an Eagle Summit
     4)  F75B-14B205-ND is a BCM for a Ford F150
     5)  15768288 is a TCM for a Chevrolet Truck

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If for some reason your unit does not have a sticker, you can call the dealership with the VIN and ask them for the original part number for your vehicle's electronic control unit. 

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Resources:

• AutoECMS Store: Buy original ECU chip for many car models.