Setting up XENTRY/DAS for Mercedes-Benz diagnostics can be a challenging endeavor, as many enthusiasts and professional technicians have discovered. If you’re facing difficulties getting your system to communicate, especially when running XENTRY on Windows 10, you’re not alone. This guide shares real-world experience in troubleshooting common problems, particularly those related to multiplexers, and offers insights to help you achieve a working diagnostic setup.
Many users opt for aftermarket XENTRY/DAS packages, often including a multiplexer like the MB STAR C3, cables, and pre-loaded software. While these packages offer convenience, they can sometimes present setup hurdles. This article details the journey of setting up XENTRY/DAS with a C3 multiplexer on a Windows 10 laptop, highlighting the troubleshooting steps taken to resolve connection issues and ultimately achieve a functional diagnostic system.
Initially, the setup involved an external USB HDD with pre-installed 05-2015 software and VMWare, paired with a multiplexer sourced separately. Despite following setup instructions, the system failed to establish a connection with the vehicle (a 2004 W220 S430). The diagnostic interface didn’t show the crucial “Connected” green light, indicating a communication problem. While the SDConnect Toolkit recognized the multiplexer as “Part D,” it reported “no connection,” suggesting that the computer could see the device, but communication beyond that point was failing.
Common advice in online forums points to potential issues such as incorrect RS232 cable types, improper COM port settings, low serial bit rate configurations, and even faulty RS232-RS485 converters within serial cables. There’s also the known limitation of C3 Part D multiplexers being potentially unsupported for software versions beyond 09/2014.
Troubleshooting began with the USB RS232 cable. Different cables, including those with and without FTDI chips, were tested to rule out cable incompatibility. To verify basic communication through VMWare, loopback tests were performed using serial communication software, confirming that the cables themselves were functional. VMWare configuration was also checked, ensuring that the “Removable Device” setting correctly assigned the USB serial cable to the virtual machine, disconnecting it from the host Windows 10 environment when XENTRY/DAS was in use.
However, the problem persisted, suggesting the issue lay either with the multiplexer itself or a more complex cabling problem beyond the basic serial connection. Seeking expert assistance, the multiplexer vendor was contacted. Utilizing remote access software (TeamViewer), a technician remotely adjusted system configurations. This intervention temporarily resolved the issue, and the green “Connected” light appeared – a moment of success. Unfortunately, this fix proved to be short-lived, as the connection failed to re-establish after restarting VMWare. The vendor attributed the problem to software and recommended purchasing a pre-configured HDD.
Undeterred and committed to finding a solution, a decision was made to acquire a new C3 multiplexer and RS232 cable from a different supplier. While awaiting the new hardware, the original multiplexer was inspected for potential hardware faults like bad solder joints, and the serial cable pinouts were carefully examined. The RS232 wiring configuration appeared non-standard, raising further questions.
Upon arrival, the new multiplexer, bundled with an RS232 cable incorporating an RS232-RS485 converter box, was connected to the existing VMWare setup. This time, the system worked! XENTRY/DAS successfully connected to the vehicle, enabling diagnostic operations and fault code reading. Interestingly, after confirming the new multiplexer’s functionality, the original multiplexer was re-tested and also began working correctly.
This experience underscores the importance of patience and methodical troubleshooting when setting up complex systems like XENTRY/DAS. While vendor instructions can be insufficient, and the system itself is undeniably intricate, a systematic approach to problem-solving, combined with persistence, can lead to success. For owners of older Mercedes-Benz vehicles with budget constraints, investing the time and effort to get XENTRY/DAS operational can be invaluable, offering significant long-term cost savings through DIY diagnostics and repairs.
