I own a routinely serviced 2012 W169... Yesterday, when regularly applying the usual force to apply breaking to full stop, four of the central dashboard LED’s turned Red (rather than their usual Amber) together with an constant audible warning. Once I took my foot off the brake and then applied the accelerator the sensor/warning stopped. No obstacles were in front of the car, and subsequent checks of the front sensors showed that they were clear of any debris. This issue did not occur when applying the brakes to slow down the car: the issue only occurred on applying the final full stop. The car is always parked in my Garage overnight. Today, I experienced the same issue. Once I had completed my shopping trip, I resolved to visit my local Mercedes workshop to discover what the likely problem might be. However, once I had completed my shopping, and started my journey to the Mercedes workshop, the issue had disappeared! Even so, on explaining the issue with the Mercedes technicians, they couldn’t offer any explanation for the problem I had been experiencing. Suggestions welcomed.