This article delves into the world of VCDS (Vag-Com Diagnostic System) cables, specifically comparing a genuine Ross-Tech cable with two different knock-off versions. We’ll examine their functionality, performance, and potential risks. This detailed analysis aims to inform those considering a budget-friendly alternative to the official VCDS system.
Decoding the Knock-Off VCDS Landscape
The quest for an affordable VCDS solution often leads to the exploration of knock-off cables. This investigation involved testing two distinct types: one based on the Atmega162 chip and another utilizing the STM32F405 chip.
The Atmega162 Cable: A Hex-CAN in Disguise
The first cable, marketed as a VCDS version 2 (V2), turned out to be a Hex-CAN cable, an older generation. Priced at $29, it required a separate loader executable flagged as malicious by VirusTotal.
Interestingly, the Atmega162 is the same chip used in genuine Ross-Tech Hex-CAN cables.
Due to its outdated functionality and the security risk associated with the loader, this cable is not recommended. Using it in a virtual machine might mitigate the malware risk, but its performance won’t match a genuine V2 cable.
The STM32F405 Cable: A Viable Alternative?
The second cable, priced at $49, utilizes the STM32F405 chip, similar to the genuine V2. Surprisingly, it functioned without a loader or modification to the VCDS software. Testing over a month revealed faster logging and data access compared to the genuine Hex-CAN.
Further investigation involved removing the STM32F405 chip and attempting to bypass its Read-Out Protection (RDP).
While successful, this revealed potential instability due to the internal RC oscillator. Future efforts will focus on using the more stable HSE clock for improved reliability. A video demonstrating the RDP bypass is available: https://youtu.be/4JFo23tYOq0
Conclusion: Proceed with Caution
While the STM32F405 cable offered surprisingly good performance, it’s crucial to acknowledge the inherent risks associated with knock-off electronics. Compatibility with future VCDS updates is uncertain, and using unmodified software version 20.4.1 is likely required. While a genuine Ross-Tech cable remains the recommended choice, the STM32F405 clone presents a functional, albeit potentially risky, alternative for budget-conscious users.
