WHEEL UNIT [DIRECT TIRE PRESSURE MONITORING SYSTEM (TPMS) (WITHOUT TPMS SET SWITCH)]
id0212002071f8
Purpose
• The wheel unit monitors the tire pressure, internal temperature of the tire, and the acceleration rate of the tire, and sends the information as RF signals.
Function
Sensor function
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• The sensing function periodically monitors the following data and sends it to the keyless receiver.
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― Tire pressure
― Internal temperature of tires
― Tire acceleration rate
― Voltage of built-in battery
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Note
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• Intervals in the tire information monitoring and information transmission to the keyless receiver vary according to the operation mode (fluctuates depending on vehicle conditions).
On-board diagnostic function
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• The on-board diagnostic function continuously performs malfunction diagnosis for each sensing function item. If the malfunction diagnosis results reveal a malfunction, the information is sent to the keyless receiver.
Construction
• The wheel unit is installed to each wheel rim using a tightened nut.
• The wheel unit also serves as a tire valve.
Structural View
Operation
• The wheel unit operates on a built-in battery, and regularly sends tire information as RF signals. The information it sends is retrieved using the sensing function that monitors tire pressure and temperature, and the on-board diagnostic function that detects the remaining battery power and sensor malfunctions.
• To maximize the life of the built-in battery, the unit uses the detected air pressure and acceleration rate to determine vehicle conditions such as driving and long stops, and operates in a mode appropriate to vehicle conditions so that battery consumption is minimized.
• Each wheel unit has its own identification code that is sent together with tire information and is used to verify which tire has abnormal tire pressure. Therefore, if a wheel unit or the instrument cluster is replaced, configuration of the identification codes is required.
