The Vcds Forum is a hub for Volkswagen, Audi, Seat, and Skoda owners seeking diagnostic solutions. A hot topic is often the use of genuine vs. clone VCDS (Vag-Com Diagnostic System) cables. This post delves into a personal experience comparing two different clone VCDS cables with a genuine Ross-Tech HEX-CAN cable. This detailed analysis will help inform your own decisions regarding VCDS hardware.
Two Clone Cables: A Tale of Two Chips
The first cable purchased was advertised as a “V2” but turned out to be a HEX-CAN clone based on the Atmega162 chip. Priced at $29, it required a separate loader program flagged as malicious by antivirus software.
Interestingly, the genuine Ross-Tech HEX-CAN cable also utilizes the Atmega162.
However, given the security risks associated with the loader, using this clone in a virtual machine is recommended. This cable ultimately proved to be functionally equivalent to a standard HEX-CAN cable, offering no advantages over an existing genuine HEX-CAN.
The second cable, based on the STM32F405 chip (similar to the genuine VCDS V2), cost $49 and promised better performance.
This cable functioned without a loader and exhibited noticeably faster logging and data transfer speeds compared to the HEX-CAN.
Cracking the STM32F405: A Deep Dive
Driven by curiosity, the STM32F405 chip was removed and analyzed. Initially locked with Read-Out Protection (RDP) level 2, access was gained using a ChipWhisperer.
A successful bypass of the RDP is demonstrated in this video:
While RDP level 1 remains, memory access is achievable by glitching the RDP1 check during bootloader communication. Further refinement of this process using CAN communication and clock glitching is planned to improve stability.
VCDS Forum Insights: Genuine vs. Clone Conclusion
This exploration highlights the complexities discussed on the VCDS forum regarding clone cables. While a budget-friendly option, the STM32F405 based clone may not support future VCDS software updates beyond version 20.4.1. For guaranteed compatibility and support, investing in a genuine Ross-Tech VCDS cable remains the recommended approach. However, this real-world testing provides valuable information for those considering clone cables for their diagnostic needs. The findings shared here contribute to the ongoing discussions within the VCDS forum and empower users to make informed choices.
