Why is the warning light still on after patching the tire?

[VonLondon]

Tire pressure warning lights do not automatically turn off just because the tire has been patched and the pressure has been refilled. A tire pressure reset is also required. Generally, after repairing the tire and refilling the pressure, holding down the tire pressure reset button will clear the warning light on the dashboard. If the reset fails, it usually indicates that there is still a tire with insufficient pressure. If all tires have adequate pressure, a diagnostic tool must be used to read the fault codes. Tire pressure monitoring systems are divided into two types, as explained below: 1. Direct detection via tire pressure sensors inside the tire: The advantage is that the system can directly indicate which wheel has low pressure. 2. Detection via wheel speed sensors by monitoring subtle differences in wheel speed to trigger an alert: This simply activates a general tire pressure warning light.