Why does a Mercedes show low tire pressure without a nail puncture?

[McIris]

There are generally three reasons why a Mercedes may display low tire pressure without a nail puncture: Tire pressure abnormality: The system typically alerts when the pressure is below 1.8bar or exceeds 3.0bar. In this case, tire inspection and pressure adjustment are required. Tire pressure monitoring system not reset: After inflating the tires, if the tire pressure monitoring system is not reset in time, it will continue to display the previously recorded data, causing the tire pressure warning light to illuminate. Simply performing a tire pressure reset will resolve this issue. Damaged tire pressure sensor: The tire pressure sensor, which monitors tire pressure, is installed inside the tire and connected to the tire inflation valve. If the sensor is damaged during driving, it can also trigger the tire pressure warning light. In such cases, the only solution is to replace the sensor with a new one. According to the international GBT2978-2008 standard, the recommended tire pressure for standard tires is 2.4-2.5bar. In winter, it is advisable to slightly increase the tire pressure by about 0.2bar based on the standard tire pressure. In summer, the tire pressure can generally be about 0.1bar lower than the standard to prevent tire blowouts due to high temperatures.