Impreza WRX STI F4-2.5L DOHC Turbo (2007)
Tire Monitoring System: Description and Operation
Transmitter (Tire Pressure Sensor)
TRANSMITTER (TIRE PRESSURE SENSOR)
Detects the tire pressure with the sensor built inside the transmitter, which is integrated with the tire air valve.
The sensor contains a battery as a power source.
The battery life is 10 years or 160,000 km (100,000 miles).
The battery cannot be replaced separately; when the battery becomes weak the whole sensor assembly must be replaced.
When the vehicle speed increases to 11 - 32 km/h (7 - 20 MPH), the roll switch built in the sensor turns ON, and the sensor starts to transmit pressure
data*1 together with the ID code*2 and function code*3",
When the switch is turned ON, the transmitter takes measurement once in every 30 seconds, and sends the result once in every minute.
When the vehicle is stopped for 15 minutes or more, the sensor enters sleep mode to minimize battery consumption.
*1: Detected tire pressure data
*2: ID code allocated to each transmitter
*3: A code indicating the current transmitter mode
The transmitter switches its mode according to its condition as follows.
These condition information are referred to as "function codes".
