Connecting your car’s OBDII port to your computer via a USB interface opens up a world of possibilities for diagnosing and modifying your vehicle. This guide focuses on using an OBDII to USB cable to flash your car’s ECU, specifically addressing common issues and questions related to the process. We’ll cover driver installation, cable connection, and power requirements to help you successfully read your car’s ROM.
Choosing the Right Driver for your OBDII to USB Cable
One of the first challenges you’ll encounter is selecting the correct driver for your OBDII to USB cable. Operating systems like Windows Vista often don’t automatically recognize these devices. You’ll likely find it listed under “Other Devices” as a USB2.0-Serial device. To resolve this, you need to manually install the appropriate driver.
For ECUFlash software and an OpenPort cable, the FTDIBUS.INF driver file is typically required. This file offers several options, including:
- OpenPort 1.3 Mitsubishi
- OpenPort 1.3 Mitsubishi (as serial port)
- OpenPort 1.3 Subaru
- OpenPort 1.3 Subaru (as serial port)
- USB Serial Converter
- USB Serial Port
Selecting “USB Serial Converter” might move the device to the “Universal Serial Bus Controllers” section, preventing it from being recognized as a COM port. The correct choice for flashing an ECU is often one of the OpenPort options, ensuring the cable functions as a serial port for proper communication with ECUFlash. Consult your cable’s documentation for the specific recommended driver. A correctly installed driver will enable ECUFlash to detect the cable connection, indicated by a responsive Read Icon in the software.
Powering the OBDII to USB Connection for ECU Flashing
Reading the ROM and flashing the ECU often have different power requirements. While you can usually read the ROM without additional power, flashing typically requires energizing a specific pin on the OBDII connector. This usually involves connecting a 12V power source to pin 16 of the OBDII connector. This provides the necessary power for the ECU to write new data.
The connection should be made with a wire of sufficient gauge to handle the current draw. While a light gauge wire might suffice, a heavier gauge wire ensures minimal voltage drop and a stable connection. Some vehicles might require higher voltage, but a 2001 Eclipse generally operates with 12V.
Troubleshooting Common Issues
During the process, you might encounter issues such as a blank or unresponsive interface in ECUFlash. This can be due to incorrect driver installation, loose connections, or insufficient power supply. Double-check all connections, ensure the correct driver is installed, and verify the 12V power supply to pin 16 if you’re flashing the ECU. A flashing Check Engine Light (CEL) isn’t always an indicator of successful connection or power. Refer to your specific vehicle and ECU documentation for expected behavior during flashing.
Conclusion
Successfully flashing an ECU using an OBDII to USB interface requires careful attention to detail, especially concerning driver selection and power requirements. By understanding these key elements and following the correct procedures, you can effectively communicate with your vehicle’s ECU and perform the necessary modifications. Remember to consult your vehicle’s specific documentation and the instructions provided with your OBDII to USB cable and flashing software for the most accurate and up-to-date information.
