For BMW enthusiasts and DIY mechanics, accessing your car’s hidden potential through coding and diagnostics is a rewarding venture. While pre-made Enet Obd2 Cables are readily available, building your own offers a cost-effective and engaging alternative. This guide from techcarusa.com will walk you through the process of creating your own ENET OBD2 cable, allowing you to connect your BMW to your laptop for advanced diagnostics and coding modifications.
Gather Your Components
Before we begin, ensure you have all the necessary tools and components. Making your own ENET cable is a straightforward project, and you’ll find most of the items readily available online or at your local electronics store.
Here’s what you’ll need:
- Soldering Kit: Essential for creating secure and lasting electrical connections.
- Multimeter: A multimeter is crucial for testing the resistor and ensuring correct connections.
- Ethernet Cable (10 Feet): A standard Ethernet cable will serve as the base for your ENET cable.
- OBD2 Connector (16-Pin): This connector will interface with your BMW’s OBD2 port.
- 510 Ohm Resistor: This resistor is a critical component for the ENET cable’s functionality.
- Cable Protector and Boot (Optional): For a cleaner and more durable finish.
You can often find combo kits that include a soldering kit and multimeter, which can be a convenient and economical option.
Step-by-Step Guide to Building Your ENET Cable
Now, let’s get into the step-by-step process of assembling your DIY ENET OBD2 cable. Follow these instructions carefully to ensure a successful build.
Step 1: Prepare the Ethernet Cable
Begin by cutting your Ethernet cable in half. This will give you two ends to work with, and for this project, we’ll only need one half. If you are using a cable protector and boot, slide them onto the cut end of the Ethernet cable now.
Step 2: Expose and Prepare the 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. Refer to the Ethernet cable wiring standard (T568B is common) to identify each wire’s corresponding pin. Tin the exposed ends of each wire using your soldering iron. This will make soldering to the OBD2 connector easier and create a stronger connection. For this ENET cable, we will not be using all eight wires. Specifically, the Blue, White/Blue, and White/Brown wires (typically associated with pins 4, 5, and 7 in some Ethernet configurations) are not required and can be trimmed.
Step 3: Prepare the OBD2 Connector
Open up the OBD2 connector housing. You’ll notice 16 pins inside, arranged in two rows of eight. These pins are numbered from 1 to 16. Familiarize yourself with the pin layout as you’ll be soldering the Ethernet wires to specific pins.
Step 4: Test the Resistor
Before soldering, it’s crucial to test your 510 Ohm resistor using your multimeter. Set your multimeter to measure resistance (Ohms) and check the resistor’s value. Ensure the reading is within the acceptable range, typically between 506 and 560 Ohms. This step confirms the resistor is functioning correctly and will provide the necessary resistance in your ENET cable circuit.
Step 5: Connect Ethernet to OBD2 – Wiring Diagram
This is the most critical step. Follow this wiring diagram precisely to connect the Ethernet wires to the correct pins on the OBD2 connector. Incorrect wiring can lead to improper function or potential damage.
| 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 |
Step 6: Solder and Assemble
Carefully solder the tinned Ethernet wires to the corresponding pins on the OBD2 connector according to the wiring diagram. Ensure each solder joint is clean and secure. After soldering the wires, solder the 510 Ohm resistor to pins 8 and 16 of the OBD2 connector. This resistor bridges these two pins.
Once all connections are soldered and cooled, carefully close the OBD2 connector housing. If you used a cable protector and boot, slide them up to the connector for a finished look and added durability.
Start Coding and Diagnosing
Congratulations! You have successfully built your own ENET OBD2 cable. Now you can connect it to your BMW and your laptop to begin exploring the world of BMW coding and diagnostics. Enjoy the enhanced control and insight into your vehicle that this DIY ENET cable provides!
