WHEEL UNIT [DIRECT TIRE PRESSURE MONITORING SYSTEM (TPMS)]
id0212002071f3
Purpose
• The wheel unit monitors air pressure, temperature and acceleration of the tire, and sends the data as RF signals.
Function
Sensing 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
― Tire temperature
― Tire acceleration
― Voltage of the built-in battery
• Intervals of tire data monitoring and data transmission to the keyless receiver differ depending on the operational mode (varies according to vehicle conditions).
Self-diagnostic function
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• The self-diagnostic function continuously performs malfunction diagnosis for each sensing function item. If any abnormality is found by the malfunction diagnosis, the data is sent to the keyless receiver.
Construction
• The wheel unit is installed to the rim of each wheel with a nut.
• The wheel unit also serves as a tire valve.
Operation
• The wheel unit operates on a built-in battery, and regularly sends tire data as RF signals. The data it sends is retrieved using a sensing function that monitors tire pressure and temperature, and a self-diagnostic function that detects battery status and sensor malfunction.
• To maximize the life of the built-in battery, the unit uses the detected air pressure and acceleration 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 data and is used to verify which tire has abnormal tire pressure. Therefore, when the wheel unit or the instrument cluster is replaced, the identification codes must be configured.
