Why does the BMW tire pressure warning light come on when the tires appear normal?
2 Answers
BMW tire pressure warning light comes on when the tires appear normal due to the following reasons: 1. Slow tire air leakage with unnoticeable symptoms; 2. System malfunction or false alarm caused by damaged sensors or receiver modules leading to incorrect tire pressure detection; 3. When the vehicle is driven for an extended period, the tire temperature increases, and due to thermal expansion, the tire pressure rises accordingly. The tire pressure warning will automatically disappear after the tires naturally cool down. Taking the 2021 BMW 3 Series as an example: The vehicle's dimensions are 4719mm in length, 1827mm in width, and 1459mm in height, with a wheelbase of 2851mm. It is classified as a mid-size car, equipped with an 8-speed automatic transmission, a top speed of 222 km/h, a fuel tank capacity of 59L, and a maximum torque of 250 N·m.
Sometimes the tire pressure warning light comes on in my BMW, but the tire surface looks normal, which initially confused me. Upon closer inspection, I found it was caused by minor issues triggering false alarms. The most common causes are TPMS sensor battery depletion or signal interference. For example, my car once had a sensor battery that ran out after a few years, especially noticeable during temperature changes. When the weather fluctuates between hot and cold, the tire pressure changes slightly but is hard to detect visually, triggering the system's alarm. Indirect monitoring systems rely on wheel speed differences to judge pressure, so uneven road surfaces or uneven tire wear can also cause false alarms. I recommend buying a reliable tire pressure gauge for regular self-checks and maintaining the correct pressure, such as 2.3 bar for the front tires and 2.5 bar for the rear tires. Don’t ignore this warning signal—drive safely and visit a professional shop to reset the system or diagnose module faults if necessary. Remember, if the alarm persists, don’t delay—prevent the risk of a tire blowout.
