GENERAL INFORMATION

OUTLINE OF CHANGES

The following change is made. The other service procedure are the same as the conventional ones.

Tyre pressure monitoring system (TPMS) is adopted. <GCC>

CONSTRUCTION DIAGRAM

Main components and functions

Parts name		Functional description
KOS-ECU		Wireless communication with the TPMS transmitter
ETACS-ECU		Wire communication with the receiver antenna <Vehicles without KOS>
Receiver antenna		Wireless communication with the TPMS transmitter <Vehicles without KOS>
TPMS transmitter		Measure tyre pressure directly, then send radio frequency signal to receiver antenna module.
Combination meter (Multi information display, TPMS warning lamp, low tyre inflation pressure warning threshold value reset function, tyre ID set changeover function)		Communicates with KOS-ECU or ETACS-ECU via CAN. Receives the warning request or warning information from KOS-ECU or ETACS-ECU, activates^* the warning lamp. Warning symbol and message is additionally displayed on the multi information display. When executing the low tyre inflation pressure warning threshold value reset function and the tyre ID set changeover function, the execution menu is displayed.

note

^*: Illuminates for tyre pressure warning. Flashes for about 1 minute and then continuously illuminated for TPMS malfunction warning.

System configuration

TYRE PRESSURE MONITORING SYSTEM (TPMS) FUNCTION

When the tyre pressure becomes under the specified value, the TPMS function warns the driver of that state by illuminating the TPMS warning lamp.

OPERATION

The signals from the TPMS transmitter are received by the KOS-ECU or ETACS-ECU via receiver antenna <without KOS>.

KOS-ECU or ETACS-ECU <without KOS> processes input signals from each TPMS transmitter as well as vehicle speed signals from the ABS-ECU <Vehicles without ASC> or ASC-ECU <Vehicles with ASC>. It receives the atmospheric pressure signal from engine-ECU, and when the atmospheric pressure is low (such as at high altitude), it calibrates the tyre pressure received from TPMS transmitter and makes a judgement of warning. When the road tyre pressure is low, it sends a warning signal causing the TPMS warning lamp to be illuminated. When the TPMS has problems, it sends a warning signal causing the TPMS warning lamp to be flashed^*.

note

^*: Change to continuous illumination after flashing for about 1 minute.

For 3 seconds after the engine switch is turned to the "ON" position, KOS-ECU or ETACS-ECU <without KOS> illuminates the TPMS warning lamp to check any breaks in the TPMS warning lamp circuit.
By connecting the M.U.T.-III to the diagnosis connector, data stored in KOS-ECU or ETACS-ECU <without KOS> (data of tyre pressure and TPMS transmitter ID, the alarm status and warning history, etc.) can be displayed and TPMS transmitter ID can be registered.

Two sets of four TPMS transmitters can be registered as sets 1 and 2.

note

If the TPMS transmitter is replaced, register the ID codes of all TPMS transmitters again about the ID set of tyre which includes the replaced transmitter using the M.U.T.-III.

Low tyre inflation pressure warning threshold value reset and tyre ID set changeover can be performed. (By registering two sets at the dealer in advance, the tyre ID set can be freely switched by operating the combination meter.)

note

When the tyre ID set is switched, the low tyre inflation pressure warning threshold value will be automatically reset.

TPMS TRANSMITTER (TYRE PRESSURE SENSOR)

The TPMS transmitter combines the valve and tyre pressure sensor in a single unit. The TPMS transmitters are mounted inside the tyres. The TPMS transmitter measures tyre pressure directly with its tyre pressure sensor and sends radio frequency signals to KOS-ECU or ETACS-ECU <without KOS>. The TPMS transmitter includes acceleration sensor that senses tyre rotation, and change tyre pressure sampling and data transmission timing when vehicle is running.

note

Use only genuine wheels. The use of non-genuine wheels may cause the improper installation of the TPMS transmitters, possibly resulting in air leakage and damage to the TPMS transmitter.

TYRE PRESSURE SAMPLING TIMING

Vehicle status	Sampling timing
At vehicle moving	once every 5 seconds
At vehicle stationary	once every 1 minute

note

Vehicle moving = vehicle speed: approximately 25 km/h or more

DATA TRANSMISSION TIMING

Vehicle status	Transmission timing
At vehicle moving	once every 1 minute^*
At vehicle stationary	once every 13 hours

If a sampled pressure varies by ±10 kPa from the last transmitted pressure value, an additional transmission will occur.

note

^*: Once every 15 seconds for first 30 transmission after vehicle starts moving.