A common challenge for high-performance car enthusiasts is gearbox reliability. One solution is converting to a more robust transmission, such as a Volkswagen DSG gearbox. This article explores troubleshooting a 2005 VW GTI DSG gearbox conversion in a 2002 Ford Focus RS using VCDS (HEX-V2).
The Ford Focus RS in question boasts a highly modified 2.0L turbocharged engine producing 600bhp and 450 ft-lbs of torque, coupled with a full carbon body resulting in a weight of 1000kg. The original H-pattern gearbox, unable to handle the immense power, was replaced with a VW DSG gearbox controlled by a Syvecs ECU. While mechanically successful, communication and diagnostic challenges arose.
The Syvecs ECU receives limited data from the DSG gearbox over the CAN bus. To gain deeper insights and resolve the issue, a VCDS HEX-V2 interface was employed. However, the lack of a corresponding VIN for the Focus RS presented a hurdle in using VCDS. The software prompted for a VIN, as shown below:
The core problem lies in the VIN mismatch. VCDS requires a valid VIN to properly communicate with the TCU. Since the Ford Focus RS doesn’t have a VW VIN, the software can’t establish a connection. The question then becomes: how to proceed with VCDS when a matching VIN isn’t available? One potential solution is entering a generic VIN with “111” as the last three digits. However, concerns arise regarding future TCU upgrades or replacements, potentially requiring a different VIN.
Furthermore, VCDS successfully identifies the gearbox control module, as evidenced in the image below:
This confirms successful communication with the TCU, but the VIN issue prevents further diagnostics. The dilemma highlights the complexities of using diagnostic tools designed for specific manufacturers on vehicles with significant modifications. Finding a workaround for the VIN requirement is crucial to unlock the full potential of VCDS in diagnosing and resolving the gearbox issue. Using VCDS with a non-matching VIN requires careful consideration of potential limitations and long-term implications. Consulting with experienced VCDS users or Ross-Tech, the developers of VCDS, is highly recommended for guidance on this specific application. Successfully navigating the VIN challenge will pave the way for in-depth diagnostics and ultimately contribute to resolving the DSG gearbox issue in the modified Ford Focus RS.
