TIRE PRESSURE WARNING SYSTEM SYSTEM DESCRIPTION

  1. DESCRIPTION OF SYSTEM

    1. The tire pressure warning ECU is integrated with the skid control ECU (brake actuator assembly).

    2. While the vehicle is driving, the tire pressure warning system receives the fluctuations in the wheel speed signals that are output by the speed sensor for the brake control system. The tire pressure warning ECU monitors the tire pressure based on the signals.

    3. When the tire pressure warning system detects that the pressure of a tire is low, it will inform the driver using the tire pressure warning light. When the ignition switch is turned off, the tire pressure warning light goes off. However, when the ignition switch is turned to ON again, the tire pressure warning light illuminates again. The tire pressure warning light remains illuminated until an initialization is performed.

  2. DESCRIPTION OF INITIALIZATION

    1. To enable this system to detect a low tire pressure, the normal tire pressure of the tires fitted to the vehicle is stored in the tire pressure warning ECU. Therefore, if a tire or wheel is replaced, the tire pressure warning ECU must be initialized.

    2. Perform initialization in the following cases:

      1. Before delivery of a new vehicle.

      2. After replacement of a tire or wheel.

      3. When a tire rotation is performed.

      4. After replacement of the skid control ECU (brake actuator assembly).

  3. TIRE PRESSURE WARNING RESET SWITCH

    1. By operating the tire pressure warning reset switch, the tire pressure warning ECU starts the system initialization.

    2. Operate the tire pressure warning reset switch only after the inflation pressures of all tires (except the compact spare tire) have been adjusted on the vehicle.

  4. FUNCTION OF MAIN COMPONENTS

    Component

    Function

    Tire Pressure Warning ECU

    • The tire pressure warning ECU is integrated with the skid control ECU (brake actuator assembly).

    • Outputs the respective signal to the combination meter when a drop in tire pressure, a system malfunction, or initialization is detected.

    • Detects a low tire pressure based on the signals from speed sensors.

    • Prohibits low tire pressure judgment when the brake pedal is depressed.

    • Is connected to the combination meter assembly via CAN bus.

    Tire Pressure Warning Reset Switch

    Starts the system initialization mode when operated.

    Combination Meter Assembly

    Transmits the ambient temperature and passenger's door courtesy light switch signals to the tire pressure warning ECU.

    Tire Pressure Warning Light

    • Illuminates to warn the driver in accordance with the signal from the tire pressure warning ECU when a low tire pressure is detected.

    • Illuminates after blinking for 1 minute to warn the driver in accordance with the signal from the tire pressure warning ECU when a system malfunction is detected.

    • Displays 2-digit Diagnostic Trouble Codes (DTCs).