The coding for a rain light sensor (RLFS) in a VW Polo 6C can differ significantly from that of a Mk7. This article explores these differences, focusing on byte coding variations and potential interpretations based on a comparison with a Mk7 RLFS (Part No SW & HW 5Q0 955 547 – label file 5Q0-955-547.CLB).
Decoding the Differences: Byte 00
A key difference lies in Byte 00. The default coding for the Mk7 is 00A8DD, while the Polo 6C presents 9038DD. In binary, the Polo’s Byte 00 (Hex90) translates to 1001 0000. Activating the “Auto Rain Close” feature involves setting Bits 1 and 2, making the lower nibble of Byte 00 equal to Hex6.
In the Mk7, the higher-order bits of Byte 00 likely control the light activation threshold. While the VCDS label file suggests Bits 3-5 govern this, it’s more plausible that Bits 3-7 are involved. This hypothesis arises because the hexadecimal values in the dropdown menu for Byte 00 require more than three bits to represent. For instance, a +20% light activation threshold (Hex08) needs five bits (01000). Therefore, the Hex90 value in the Polo 6C might represent a specific light activation threshold variant.
Byte 1-2: Vehicle Type Definition?
Bytes 1-2 in the Mk7 seemingly define the vehicle type. It’s possible that the Hex 38DD value in the Polo 6C corresponds to its specific model identification.
Conclusion: Further Investigation Needed
While these comparisons provide insights, definitively interpreting the VW Polo 6C’s RLFS coding requires further investigation. Access to the Polo 6C’s specific label file within VCDS would offer more conclusive answers regarding the precise function of each bit and byte. This information is crucial for accurately customizing the rain light sensor’s behavior in a VW Polo 6C.
