TIRE PRESSURE MONITORING SYSTEM (TPMS) CONSTRUCTION/OPERATION

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Construction

• The TPMS consists of wheel units that detect air pressure, temperature and acceleration of each tire, and a TPMS control module that receives data (RF signals) sent from the wheel units to monitor the air pressure of each tire.

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Operation

• The wheel unit installed to each wheel sends data on air pressure, temperature and acceleration of each tire by means of RF signals. The keyless receiver receives these signals with a built-in antenna.
• With advanced keyless entry and start system: Signals received by the keyless receiver are transmitted to the instrument cluster via the keyless CM.
• With keyless entry system: Signals received by the keyless receiver are transmitted to the instrument cluster.
• The instrument cluster monitors the air pressure of each tire based on the tire data sent from each wheel unit. If the instrument cluster detects an excessive drop in air pressure or flat tire, the instrument cluster illuminates the TPMS warning light.

Component Parts/Function

Part name | Function
--- | ---
Wheel unit | • Monitors air pressure, temperature, and acceleration of each tire, and sends RF signals. • Sends data if any abnormality is detected in the wheel unit.
Keyless receiver | • With advanced keyless entry and start system: Send the RF signals received from the wheel unit to the keyless CM. • With keyless entry system: Send the RF signals received from the wheel unit to the instrument cluster.
Keyless CM (with advanced keyless entry and start system) | • Receives data from the keyless receiver. • Sends data to the instrument cluster.
PCM | Vehicle speed signal | • Inputs vehicle speed signals to the instrument cluster via CAN communication.
Instrument cluster |  | • Receives data from keyless CM (with advanced keyless entry and start system) or keyless receiver (with keyless entry system) and monitor the air pressure of each wheel. If it determines from those signals that tire pressure is abnormal, it controls the TPMS warning light to alert the driver.
TPMS warning light | • If the instrument cluster detects abnormal air pressure or any abnormality in the system, the light is illuminated to alert the driver.