Frustrated by import restrictions or high prices for an ENET cable to connect your BMW to your laptop? Don’t worry, you can easily build your own Enet Obd2 Cable at home using readily available components. This guide will walk you through the process step-by-step, allowing you to perform diagnostics and coding on your BMW without breaking the bank. This DIY approach is perfect for car enthusiasts and those looking to delve into the world of BMW diagnostics and modifications.
Materials You’ll Need to Make Your ENET OBD2 Cable
Before you begin, gather these essential tools and components. You can find most of these items online or at your local electronics store.
- Soldering Kit: Essential for creating secure and lasting electrical connections.
- Multimeter: A crucial tool for testing the resistor and ensuring proper electrical flow.
- Ethernet Cable (10 Feet): Provides the core wiring for your ENET cable.
- OBD2 Connector (16 Pin): This connector interfaces with your BMW’s OBD2 port.
- 510 Ohm Resistor: A necessary component for the ENET circuit.
- Cable Protector and Boot (Optional but Recommended): For a more professional and durable finish.
For convenience, you might consider a combo kit that includes a soldering kit, multimeter, and cutter.
Step-by-Step Guide to Making Your ENET OBD2 Cable
Follow these detailed steps to assemble your DIY ENET OBD2 cable.
Step 1: Prepare the Ethernet Cable
Begin by cutting your 10-foot Ethernet cable in half. This will give you two five-foot cables, providing ample length for connecting your laptop to your BMW. If using cable protectors and boots, slide them onto one end of the Ethernet cable now. This is easier to do before you start stripping wires.
Step 2: Expose and Prepare Ethernet Wires
Carefully remove the outer plastic jacket from the cut end of the Ethernet cable. You’ll want to expose a few inches of the internal wires. Inside, you’ll find eight wires, each with a different color. These color codes are important for correctly wiring your ENET OBD2 cable.
Identify each wire color and its corresponding pin number based on the T568B standard (commonly used for Ethernet cables). It’s crucial to know which color wire corresponds to each pin for accurate connection. Once identified, use your soldering iron to tin the exposed tips of each wire. Tinning makes soldering easier and creates a better electrical connection. For this DIY ENET cable, you will not need all eight wires. Specifically, the Blue, White/Blue, and White/Brown wires (typically associated with pins 4, 5, and 7 in Ethernet cabling) are not required and can be trimmed.
Step 3: Open the OBD2 Connector
Carefully open the OBD2 connector. These connectors usually come in two halves that snap together. Inside, you’ll see 16 pins arranged in two rows of eight, numbered 1 through 16. Refer to the pinout diagram in Step 5 to understand which pins you’ll be soldering to.
Step 4: Test the Resistor
Before soldering, it’s important to verify the resistance of your 510 Ohm resistor using your multimeter. Set your multimeter to measure resistance (Ohms) and test the resistor. Ideally, the reading should be close to 510 Ohms, within a tolerance range of roughly 506-560 Ohms. This ensures you have the correct resistor value for the ENET circuit.
Step 5: Solder the Connections
Now, carefully solder the Ethernet wires to the corresponding pins on the OBD2 connector according to the pin diagram below. This diagram is crucial for ensuring your ENET OBD2 cable works correctly.
ENET OBD2 Cable Pinout:
| 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 |
After soldering the wires, you need to solder the 510 Ohm resistor across pins 4 and 5 AND pins 8 and 16 of the OBD2 connector. This resistor is a critical part of the ENET circuit and ensures proper communication.
Step 6: Final Assembly and Testing
Once all soldering is complete and you’ve allowed the connections to cool, carefully close the OBD2 connector housing. Ensure all wires are neatly tucked inside and the connector snaps together securely. If you used a cable protector and boot, slide the boot over the OBD2 connector for a clean and protected finish.
Now your DIY ENET OBD2 cable is ready! Connect it to your BMW’s OBD2 port and the Ethernet port on your laptop. You can now use compatible software to perform coding, diagnostics, and other functions on your BMW. Enjoy the power of DIY car diagnostics and coding with your homemade ENET OBD2 cable!
