General Information

Component Location





General Description




This transmitter is a transmitter device with tire valve, which is mounted in the valve hole of the wheel rim and transmits the pressure and temperature inside the tire, the battery voltage of the transmitter, and the tire identification code (ID) at normal and abnormal condition with the radio wave (RF) that conforms to the used area. Also this device has a countermeasure function such as the random delay of transmission time so that the RF signal from each tire will not interfere due to simultaneous transmission. Wheel sensors shall support usage on steel or aluminum rims.
Sensor transmissions continue when sensor status is 'Normal Fixed State'. Sensor transmissions stop when sensor status is 'Storage State' or the sensor battery runs out. The transmitter should transmit data at vehicle speeds between 0 mph (0 kph) and 186 mph (300 kph). Operating Temperature Range is -40 to 248 °F (-40 to 120 °C). Transmitter shall enter thermal shutdown once the measured temperature is greater than or equal to 257 °F (125 °C). The accuracy of the sensor is -9/12.6 degree Fahrenheit (-5/7 degree Celsius) at this temperature, therefore the actual temperature may be 244.4 degree Fahrenheit (118 degree Celsius). The sensor shall exit thermal shutdown once the temperature is less than or equal to 212 °F (100 °C). The transmitter shall have the capability to measure the internal battery voltage as an indicator of the end of life of the sensor. Since the unit is sealed, this parameter cannot be verified with a production unit.
[Tire Pressure Monitoring]
When 4 sensors have been learned as road wheels, it shall not be possible to learn new road wheel sensors on the same Ignition cycle. In normal mode low line, tire pressure and temperature shall be transmitted every 3 minutes 20s nominally independent of vehicle operation. Monitoring shall be every 20s. If sensor detects rapid deflation, then RF messages will be transmitted every 4s for 1 minute duration. Communication from wheel sensors shall be via RF at a frequency of 315 MHz, 5 kBaud.
Tire pressure measurement tolerance shall be ±7 kPa from 32 to 122 °F (0 to 50 °C) and ±17.5 kPa from -40 to 248 °F (-40 to 120 °C) with a range of 100 to 450 kPa. Tire temperature measurement tolerance shall be ±5.4 °F (±3 °C) from -4 to 158 °F (-20 to 70 °C) and to ±9 °F (±5 °C) from -40 to 194 °F (-40 to 90 °C) and -9/12.6 degree Fahrenheit (-5/7 degree Celcius) from -40 to 248 degree Fahrenheit (-40 to 120 degree Fahrenheit).

DTC Description

This DTC indicates that the sensor has seen a temperature in excess of 230 °F (110 °C). At 257 °F (125 °C), the sensor will shut down and the warning is therefore so that the driver knows that there is a problem with the vehicle that may affect tire performance.

DTC Detecting Condition