Toyota has selected EnTire Solutions LLC to supply direct tire pressure monitoring systems for the 2007 Sienna. EnTire is a joint venture formed by TRW Automotive and Michelin. It also supplies tire pressure monitoring systems for Honda, Hyundai, Kia and Fiat.
EnTire Solutions' direct TPM system uses a battery-powered pressure sensor mounted on the valve stem inside the wheel. The sensor communicates tire pressure and temperature information to a vehicle-mounted receiver via a radio signal.