VW Up Rain Sensor Failure Causes Multiple System Issues

Had this exact issue with a 2016 VW Polo TSI. The malfunctioning sensor system showed similar symptoms, no auto wiping, failed light control, and instrument cluster issues. The root cause was bubbles forming under the gel pad that houses the rain sensor unit. This creates an air gap that prevents proper sensor calibration. The auto sensor completely loses its ability to detect rain or light changes, triggering various electrical fault codes. The fix required: Complete removal of the old sensor unit, Thorough cleaning of the mounting surface, Installation of a new sensor assembly with fresh gel pad, Full electrical system calibration This is not a DIY job as it involves working with the windshield and precise sensor calibration. The repair was substantial since the sensor unit is integrated with multiple vehicle systems. Without proper repair, it can affect: Automatic wiper operation, Headlight control, Dashboard dimming, Various comfort features Professional repair is essential as incorrect installation can lead to water leaks or further electrical issues. The sensor needs proper positioning and programming to communicate correctly with the car's systems.

Thanks for sharing your experience with the rain sensor replacement. My VW Up has been running fine since the repair about 4 months ago. The symptoms and repair process matched exactly what you described, it was definitely the faulty sensor unit causing all those electrical gremlins. Just curious, can you remember roughly what the total repair cost was for your car? My bill seemed steep but maybe thats standard for this kind of car electronics work. Also wondering if youve had any other sensor-related issues pop up since getting it fixed? The rain detection system has been working flawlessly on mine after the repair, though I keep a close eye on the car components around the windshield area now just to catch any early warning signs of sensor problems.

Great to hear your VW Up got sorted out with the rain sensor repair. After my visit to the mechanic, they completely resolved the rain-light sensor fault. The total came to 62€ which was mainly for fixing those troublesome bubbles under the gel pad near the windshield. The car electronics have worked perfectly since the repair, no more sensor issues or warning lights. The rain detection system responds correctly now, and all the connected features like auto wiping and light control are back to normal. For anyone else facing similar problems, getting those bubbles fixed properly is crucial for the sensor to work. Trying to save money with temporary fixes usually leads to more car components failing down the line. A proper repair by a qualified technician is worth the investment.

Thanks everyone for the detailed feedback. Just wanted to share my final update on how this repair went for me. Took the car to a certified VW shop last week and the whole sensor replacement came to 420€. Bit more than I hoped but the work was thorough. The mechanic showed me the old sensor unit and you could clearly see the gel pad damage causing the malfunction. They had to carefully remove the old unit, clean everything properly, and calibrate the new sensor components. Took about 3 hours total. All the automatic features are working perfectly now, the wipers respond to rain, lights adjust automatically, and the dashboard dimming is back to normal. No more error codes or sensor faults showing up. While it wasnt cheap, at least I know it was done right this time. The shop explained every step and even showed me the diagnostic readings before and after. Much better experience than my previous mechanic visits. Really appreciate all the advice that helped me understand what was actually wrong with the car. Having that knowledge made me more confident when discussing the repair with the shop.