Facing import restrictions and high prices for an ENET cable to connect your BMW to a laptop? Don’t worry, you can easily build your own ENET (Ethernet to OBD2) cable at home using readily available components from Amazon. This guide will walk you through each step to create a functional and reliable cable for BMW coding and diagnostics.
To get started, you’ll need a few essential tools and parts. Here’s a list of what you’ll need for this DIY project:
-
Soldering Kit: Essential for making secure and lasting electrical connections.
https://amzn.to/2JVcr1h -
Multimeter: To test the resistor and ensure correct electrical values.
https://amzn.to/34dnAB8 -
Ethernet Cable (10 Feet): Provides the base wiring for your Obd2 To Ethernet Cable.
https://amzn.to/3adGmw3 -
OBD2 Connector (Male): This connector interfaces with your car’s OBD2 port.
https://amzn.to/3qYUVJR -
510 Ohm Resistor: A crucial component for proper communication in BMW ENET cables.
https://amzn.to/3ad8WO8 -
Soldering Kit + Multimeter + Cutter Combo (Optional): A convenient kit if you need all the basic tools.
https://amzn.to/3qRcQSO
Step 1: Prepare the Ethernet Cable
Begin by cutting your Ethernet cable in half. This gives you two ends to work with, and for this project, you’ll only need one half. Slide the cable protector and boot onto the cut end of the Ethernet cable. This will provide strain relief and protect the connection point once finished.
Step 2: Expose and Prepare Ethernet Wires
Carefully remove the outer plastic jacket of the Ethernet cable to expose the internal wires. You’ll see eight wires, each with a different color. Identifying these color codes is crucial for correct wiring. Tin the tips of these exposed wires using your soldering iron. Tinning makes soldering to the OBD2 connector easier and ensures a better electrical connection. Unnecessary wires (pins 4, 5, and 7 – Blue, White/Blue, and White/Brown) can be cut off as they are not needed for this OBD2 to Ethernet cable configuration.
Step 3: Open the OBD2 Connector
Next, open up the OBD2 connector. Examine the inside, and you’ll notice 16 pins, arranged in two rows of eight. These pins are numbered 1 to 16, which is important for correctly connecting the Ethernet wires.
Step 4: Test the Resistor
Before soldering the resistor, use your multimeter to test its resistance. A 510 Ohm resistor is specified, and you should ensure it reads within a close tolerance, ideally between 506 and 560 Ohms. This step confirms the resistor is within the correct operating range for your OBD2 to Ethernet cable.
Step 5: Solder Ethernet Wires to OBD2 Connector
Refer to the pinout diagram below to correctly solder the Ethernet wires to the OBD2 connector pins. This diagram is your guide to ensure each wire goes to the correct pin for proper communication between your BMW and laptop.
Follow this wiring configuration:
| Ethernet Pin | Wire Color | OBD2 Pin |
|---|---|---|
| Pin 1 | White/Orange | Pin 3 |
| Pin 2 | Orange | Pin 11 |
| Pin 3 | White/Green | Pin 12 |
| Pin 6 | Green | Pin 13 |
| Pin 8 | Brown | Pin 4 & 5 |
Finally, solder the 510 Ohm resistor across Pins 8 and 16 of the OBD2 connector. This resistor is essential for the ENET communication protocol.
Final Steps
After completing all the soldering, carefully close the OBD2 connector cover, ensuring no wires are pinched. Your DIY OBD2 to Ethernet cable is now ready! Connect it to your BMW’s OBD2 port and your laptop to start coding or diagnosing your vehicle. Enjoy the capabilities of professional-level diagnostics and customizations right at home!
