Good evening everyone, I own a 2020 Mazda2 Skyactiv-G 90 Mild Hybrid Evolve. There aren’t many of them around in my area, so as soon as I saw the first opportunity and listing, I immediately bought it from a private seller.
The car had—and still has—a problem related to the brake/light switch sensor. The seller had already contacted the only authorized Mazda service center in the area to resolve the issue, namely a non-original sensor that was causing a compatibility error. He reassured me that it would be a simple fix and that he would pay for the part himself after the sale, once it was replaced. Naively and without asking too many questions, I went ahead and bought the car.
I’m here because the story didn’t end well: replacing the part (€100) did not solve the problem, and Mazda quoted me €450 just for analysis and investigation of the possible cause (according to them, a wiring issue).
I’ll explain the problem scenario:
The car works normally—it brakes, the brake lights come on, everything seems fine. After a few braking events, randomly, three warning lights appear: the engine light, the triangle warning (generic problem), and the anti-collision system (SCBS deactivated).
Over the past few months I’ve researched the issue, studied manuals, wiring diagrams, and other material to try to understand the source of the problem. I bought an OBD2 device and learned how to use FORScan to read brake/light sensor signals, voltages, and other data, but everything seems normal (if you want, I can share these readings).
I’m coming to the conclusion that it might be a damaged or corroded ground connection of the BCM, which intermittently alters the signal and therefore not constantly.
I’d like to ask if any of you have had similar issues with this sensor or with other sensors.
If you want, I can also attach the error readings so I can provide the exact fault codes.
Thank you for your attention
The car had—and still has—a problem related to the brake/light switch sensor. The seller had already contacted the only authorized Mazda service center in the area to resolve the issue, namely a non-original sensor that was causing a compatibility error. He reassured me that it would be a simple fix and that he would pay for the part himself after the sale, once it was replaced. Naively and without asking too many questions, I went ahead and bought the car.
I’m here because the story didn’t end well: replacing the part (€100) did not solve the problem, and Mazda quoted me €450 just for analysis and investigation of the possible cause (according to them, a wiring issue).
I’ll explain the problem scenario:
The car works normally—it brakes, the brake lights come on, everything seems fine. After a few braking events, randomly, three warning lights appear: the engine light, the triangle warning (generic problem), and the anti-collision system (SCBS deactivated).
Over the past few months I’ve researched the issue, studied manuals, wiring diagrams, and other material to try to understand the source of the problem. I bought an OBD2 device and learned how to use FORScan to read brake/light sensor signals, voltages, and other data, but everything seems normal (if you want, I can share these readings).
I’m coming to the conclusion that it might be a damaged or corroded ground connection of the BCM, which intermittently alters the signal and therefore not constantly.
I’d like to ask if any of you have had similar issues with this sensor or with other sensors.
If you want, I can also attach the error readings so I can provide the exact fault codes.
Thank you for your attention
