So my brother was got a "low air pressure reading" this weekend on his 07 Tahoe, he put air in it and at the same time his wife hit the "reset" button. The truck beeped twice and now the service tire pressure monitor system light comes across the warning area.

we just reset all 4 wheels and still reads the same thing. We disconnected the battery for 10 min, still says the same thing.

anyone know what else it could be or how to fix it?

thanks.