TIRE PRESSURE WARNING SYSTEM

FUNCTION OF MAIN COMPONENTS

Component		Function
Tire Pressure Warning Valve and Transmitter		Detects the tire inflation pressure and temperature of the tire and transmits the measured value and ID code to the tire pressure warning ECU and receiver.
Tire Pressure Warning ECU and Receiver		Receives the data from each tire pressure warning valve and transmitter and monitors its tire inflation pressure. When the tire pressure warning ECU and receiver detects a drop in tire inflation pressure, a system malfunction, or initialization mode, it outputs the respective signal to the combination meter assembly.
Tire Pressure Warning Reset Switch		The current tire pressures are stored in the tire pressure warning ECU and receiver as set pressures when the tire pressure warning reset switch is operated.
Main Body ECU (Multiplex Network Body ECU)		Receives the signal from tire pressure warning ECU and receiver and outputs it to the combination meter assembly via CAN communication.
Combination Meter Assembly		Transmits the vehicle speed signal to the tire pressure warning ECU and receiver.
Combination Meter Assembly	Tire Pressure Warning Light	Warns the driver by illuminating or blinking for 1 minute in accordance with the signal from the tire pressure warning ECU and receiver.

FUNCTION

Warning Function

The tire pressure warning ECU and receiver has 2 warning methods, depending on the condition detected.

The table below shows the warning methods for the warning light in the combination meter assembly.

Detection Condition	Tire Pressure Warning Light
The tire pressure warning ECU and receiver has detected that a tire inflation pressure has become lower than the threshold.	Illuminates*1
The tire pressure warning ECU and receiver has detected a malfunction in the system.	Stays on after blinking for 1 minute*2

*1: If the tire pressure warning light illuminates, adjust the tire inflation pressure.

*2: If the tire pressure warning light stays on after blinking for 1 minute, the system is malfunctioning and must be repaired to turn off the light. For details, refer to the Repair Manual.

Initial Check Function
1. After the ignition switch is tuned to ON, the tire pressure warning ECU and receiver illuminates the tire pressure warning light for 3 seconds to check the warning light circuits.
Initialization Function
1. The warning threshold is calculated from the tire pressure warning valve and transmitter at the time of initialization and memorized in the tire pressure warning ECU and receiver. Therefore, the tire pressure warning ECU and receiver should be initialized after:
  - The recommended tire inflation pressure changes due to changes in vehicle weight, speed conditions or tire size.
  - Replacement of the tire pressure warning ECU and receiver or a tire pressure warning valve and transmitter.
  - The tires are rotated on a vehicle with different recommended tire inflation pressures for the front and rear tires.
  - The tire pressure is adjusted.
2. Initialization starts after the tire pressure warning reset switch is pressed and the tire pressure warning light illuminates slowly 3 times.
3. Before performing initialization, adjust the tire inflation pressure to the recommended pressure when the tires are cold. For details, refer to the Repair Manual.
4. The tire pressure warning reset switch is not used to cancel the warning. Do not press the tire pressure warning reset switch to turn off the tire pressure warning light.

DIAGNOSIS

To inform the driver when the tire pressure warning ECU and receiver detects a malfunction in the system, the tire pressure warning ECU and receiver will blink the tire pressure warning light for 1 minute, after which the light will stay on. It will also store the Diagnostic Trouble Codes (DTCs) in memory.
5-digit DTCs can be read by connecting the Global TechStream (GTS) to the DLC3. For details, refer to the Repair Manual.