Connecting your BMW to a laptop for diagnostics and coding often requires a specialized Ethernet To Obdii Cable. This cable, also known as an ENET cable, can be expensive. However, with a few readily available components and some basic soldering skills, you can create your own Ethernet to OBDII cable at home. This guide provides a step-by-step walkthrough of the process.
Gathering the Necessary Materials
Before you begin, ensure you have the following items:
- Soldering Kit: A basic soldering kit includes a soldering iron, solder, and a stand. A multimeter is also recommended for checking resistor values.
- Multimeter: Used to test the resistance of the resistor to ensure it’s within the required range.
- 10 Feet Ethernet Cable: Provides ample length for connecting your laptop to the vehicle’s OBDII port.
- OBD2 Connector: A female OBD2 connector housing will be used to create the cable’s OBDII end.
- 510 Ohm Resistor: This specific resistor value is crucial for proper communication between the car and laptop. You may need to use a multimeter to check that your resistor is within the required 506-560 ohm range.
- Wire Strippers and Cutters: Essential for preparing the Ethernet cable and resistor.
Constructing the Ethernet to OBDII Cable
Step 1: Prepare the Ethernet Cable
Cut the Ethernet cable in half. Install a cable protector and boot on each end of the cut cable to provide strain relief and a professional finish.
Step 2: Expose and Tin the Ethernet Wires
Carefully strip the outer jacket of the Ethernet cable to expose the individual wires. Identify each wire by its color. Using the soldering iron, lightly tin the exposed ends of each wire to facilitate soldering. You won’t need the blue, white/blue, and white/brown wires for this project, so these can be trimmed back.
Step 3: Prepare the OBD2 Connector
Open the OBD2 connector housing. Familiarize yourself with the pin layout, noting the numbering from 1 to 16.
Step 4: Verify Resistor Value
Using the multimeter, confirm that the 510 Ohm resistor’s value falls within the acceptable range of 506-560 Ohms. This step is crucial for ensuring proper functionality.
Step 5: Soldering the Connections
Refer to the following pinout diagram to solder the Ethernet wires to the corresponding pins on the OBD2 connector:
- Ethernet Pin 1 (White/Orange) to OBD2 Pin 3
- Ethernet Pin 2 (Orange) to OBD2 Pin 11
- Ethernet Pin 3 (White/Green) to OBD2 Pin 12
- Ethernet Pin 6 (Green) to OBD2 Pin 13
- Ethernet Pin 8 (Brown) to OBD2 Pin 4 and 5
Finally, solder one leg of the 510 Ohm resistor to pin 8 and the other leg to pin 16 of the OBD2 connector.
Step 6: Final Assembly
After all connections are securely soldered, carefully close the OBD2 connector housing. Your custom Ethernet to OBDII cable is now complete.
This DIY Ethernet to OBDII cable allows you to connect your BMW to a laptop for various tasks, including diagnostics, coding, and programming. Remember to always double-check your connections before use. While this guide provides detailed instructions, working with electronics requires caution and attention to detail.
