TIRE PRESSURE WARNING SYSTEM SYSTEM DESCRIPTION


  1. DESCRIPTION OF SYSTEM


    1. When the tire pressure warning system detects that the tire pressure of a tire becomes lower than the threshold, it will inform the driver using a warning light.

    2. The tire pressure warning antenna receives the transmitter ID, temperature and tire pressure information from the tire pressure warning valve and transmitters shown in the following illustration. The tire pressure warning ECU and receiver uses this information to determine when the pressure in one of the tires has dropped.

      A01GNYGE02
    Text in Illustration
    *A w/ Spare Tire - -
    *1 Tire Pressure Warning ECU and Receiver *2 Tire Pressure Warning Valve and Transmitter
    *3

    Combination Meter

    - Tire Pressure Warning Light

    		 *4 Tire Pressure Warning Antenna (for Roof Side)
    *5

    for ECE-R64 Type:

    Tire Pressure Warning Antenna (for Front Side)

    		 *6 Tire Pressure Warning Reset Switch
    *7 Tire Pressure Monitor Initiator Driver *8 Front Tire Pressure Monitor Initiator
    *9 Rear Tire Pressure Monitor Initiator - -
    *a Front *b Tire Position Identification Signal

  2. DESCRIPTION OF TIRE POSITION IDENTIFICATION FUNCTION


    1. The deterioration of signal strength at a distance (when a transmitter is close, the signal is strong, and when a transmitter is far, the signal is weak) is used to determine position. Position identification is performed when the engine switch is turned on (IG), when the vehicle starts moving (if position could not be determined when the engine switch was turned on (IG)), when initialization is performed and when ID registration is completed.

      For front position identification (rear position identification is performed in the same way):


      1. The front tire pressure monitor initiator sends a position identification signal to all of the tire pressure warning valve and transmitters.

      2. The tire pressure warning valve and transmitters respond to the received position identification signal by sending a signal to the tire pressure warning antenna indicating the strength of the received signal.

        Tech Tips

        The strength of the signals is different because the distance between the front tire pressure monitor initiator and each tire is different.

      3. The tire pressure warning antenna receives the signal strength information signals from the tire pressure warning valve and transmitters, and then the tire pressure warning ECU and receiver associates them with their correct position based on the received information.

  3. DESCRIPTION OF REGISTRATION


    1. When tires and wheels are replaced, always ensure that each transmitter ID is correctly registered.

    2. When one or more tire pressure warning valve and transmitters or the tire pressure warning ECU and receiver is replaced, the transmitter IDs for all of the tire pressure warning valve and transmitters must be re-registered. Before registering the transmitter ID of the new tire pressure warning valve and transmitter, check the Data List and record all of the transmitter IDs that are already registered.

  4. TIRE PRESSURE WARNING RESET SWITCH


    1. By operating the tire pressure warning reset switch, the tire pressure warning ECU and receiver can be set to issue a warning at an inflation pressure that corresponds to the type of tires fitted to the vehicle. Therefore, the warning threshold must be set to the proper value in order to comply with local regulations.

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

  5. DESCRIPTION OF INITIALIZATION


    1. During initialization, the tire pressure warning valve and transmitters measure the inflation pressure of the tires, and register the signals that are transmitted into the tire pressure warning ECU and receiver at a frequency of about once per minute. The initialization process is completed when signals from all tires have been received.

    2. Perform initialization in the following cases:


      1. Before delivery of a new vehicle.

      2. After replacement of the tire pressure warning ECU and receiver*.

      3. After replacement of a tire pressure warning valve and transmitter*.

      4. When the specified tire pressure changes due to the use of a different size or type of tire.

      5. When the specified tire pressure changes due to a change in the vehicle load, the speed range that the vehicle will be used in, etc.

      6. When a tire rotation is performed and the specified tire pressures are different for the front and rear of the vehicle.

        Tech Tips

        *: Perform initialization after the transmitter ID registration is completed.

  6. DESCRIPTION OF ID SWITCHING FUNCTION (w/ ID Switching Function)


    1. By designating the ID registration location, it is possible to register transmitter IDs for both the main and 2nd sets of tires.

    2. If IDs are registered for both the main and 2nd tire sets, it is possible to switch between the two sets of tires by pressing the tire pressure warning reset switch Click here.

      Note

      Be careful as the method to perform ID switching differs from the method to perform initialization.

    3. When reading the status for a registered ID, it is only possible to read the ID information for the selected set of tires.

      Tech Tips

      In order to read the IDs registered for the main tire set, it is necessary to set the ID selection setting to "Main". Likewise, it is necessary to set the ID selection setting to "2nd" in order to read IDs registered for the 2nd set of tires.

  7. FUNCTION OF MAIN COMPONENTS

    Component Function
    Tire Pressure Warning ECU and Receiver

    • Receives the data from the tire pressure warning antenna and monitors the tire pressure.

    • When the tire pressure warning ECU and receiver detects a drop in the tire pressure, a system malfunction, or initialization mode, it outputs the respective signal to the combination meter.

    • When the tire pressure warning ECU and receiver detects that the vehicle speed signal is lost, it determines that the vehicle is being driven.

    • Commands the tire pressure monitor initiator driver to perform position identification.

    • Associates each tire pressure warning valve and transmitter with a certain position (left/right and front/rear) based on the signal strength information received from the tire pressure warning antenna, and outputs the tire pressure information to the multi-information display.
    Tire Pressure Warning Valve and Transmitter

    • Detects the pressure and internal temperature of the tire and transmits the measured values and the ID code to the tire pressure warning antenna.

    • Receives position identification signals from the front and rear tire pressure monitor initiators and sends a signal indicating the signal strength to the tire pressure warning antenna.

    • Tire Pressure Warning Antenna (for Roof Side)

    • Tire Pressure Warning Antenna (for Front Side)

    		 Receives the tire pressure warning valve and transmitter signal and transmits this data to the tire pressure warning ECU and receiver.
    Tire Pressure Warning Reset Switch

    • Stores the warning threshold determined by the current tire pressure as the set pressure in the tire pressure warning ECU and receiver when operated.

    • Pressing this switch performs ID switching (w/ ID Switching Function).

    • Front Tire Pressure Monitor Initiator

    • Rear Tire Pressure Monitor Initiator

    		 Sends a position identification signal to the tire pressure warning valve and transmitters.
    Tire Pressure Monitor Initiator Driver Operates and monitors the front and rear tire pressure monitor initiators.
    Combination Meter Transmits the vehicle speed signal to the tire pressure warning ECU and receiver.
    Tire Pressure Warning Light

    • Illuminates after blinking for 1 minute to warn the driver in accordance with the signal from the tire pressure warning ECU and receiver.

    • Displays 2-digit Diagnostic Trouble Codes (DTC).
    Multi-information Display Displays the tire pressure of each tire.
    Multi-information Switch (Steering Pad Switch Assembly) Houses the switches to operate the multi-information display.