Replacing the body control module (BCM), often referred to as the hex09 module by VCDS users, in an MQB platform Volkswagen Group (VAG) car like a Golf Mk7 GTE, involves more than just swapping the physical unit. This article delves into the complexities of this process, focusing on component protection and coding adaptations necessary for a successful retrofit.
Component Protection and Initial Steps
The first hurdle in replacing a hex09 module is Component Protection (CP), a security feature in MQB cars. Installing a new module triggers CP errors in both the hex09 (central electrics) and hex19 (gateway) modules. These errors prevent the new module from functioning correctly and must be cleared by a VAG dealer or authorized agent using official tools. Attempting to bypass this step will render the new module unusable.
Coding Challenges: Long Code vs. Adaptation Channels
Once the CP issue is resolved, the next challenge is matching the coding of the new hex09 module to the old one. This requires a comprehensive record of the original module’s coding before removal.
VAG significantly changed the hex09 module’s coding structure around mid-2016. Earlier modules used long coding, a string of hexadecimal digits representing various software switches. Newer modules utilize adaptation channels, a database of individual settings.
Determining whether your modules use long coding or adaptation channels is crucial. This information is readily available using a diagnostic tool like VCDS or OBD11. If both modules use long coding, comparing and adjusting individual switches is relatively straightforward. However, if transitioning from long coding to adaptation channels, you’ll need to map the old long code settings to the corresponding adaptation channels in the new module. This process is considerably more complex.
Aligning Adaptation Channels: Data Parsing for Efficient Comparison
Adaptation channel alignment can be daunting, as the hex09 module may have up to 2,600 channels. To simplify this task, “data massaging” or parsing is highly recommended. This involves converting the adaptation channel data into a flat file format, such as a .CSV (Comma Separated Variables) file. This allows for digital comparison using spreadsheet software like Microsoft Excel or database programs like Microsoft Access.
VCDS offers a built-in function called “ADMAP” to export adaptation channel data in a .CSV format, facilitating easy parsing. While OBD11’s backup files are not as readily parsed, third-party tools are available to convert the data into a usable format.
Module Variations and Informed Guesswork
Even with meticulous data parsing, perfect alignment may be impossible if the old and new modules have different part or software numbers. This is because different module versions may have unique adaptation channels not present in the other. In such cases, informed guesswork based on the function of each channel and the desired vehicle configuration is necessary. Factors like the “headlight upgrade to FL” mentioned in the original query will require specific adjustments.
Conclusion: Professional Assistance Recommended
Replacing and coding a Vcds Body Control Module in an MQB platform car is a complex procedure requiring specialized knowledge and tools. While this article provides a general overview, seeking professional assistance from a VAG dealer or experienced technician is strongly recommended. Incorrect coding can lead to unexpected vehicle behavior and potential malfunctions. Component Protection alone necessitates dealer intervention, making professional help essential for a successful outcome.
