TSB: 2015 model year GS 350 and GS 450h vehicles are equipped with a direct-type Tire Pressure Warning System (TPWS). Each tire (except the spare tire) has a tire pressure warning valve/sensor that measures tire pressure. The data is transmitted to the Tire Pressure Warning System antenna/receiver and then to the Tire Pressure Warning System ECU. During Pre-Delivery Service (PDS), the tire pressure warning valves/sensors must be activated and the system initialized according to the procedure in this bulletin.