After the vehicle speed is less than 20 km/h for 12 minutes, the system enters "parking mode". In parking mode, the tire pressure sensors transmit a coded signal to the module every 13 hours. If the tire pressure drops by more than 0.6 bar, the sensor transmits a signal more frequently.
In standby mode, the spare tire pressure sensor sends signals every 132 hours in the same way as the impeller sensors. If the tire pressure drops by more than 0.6 bar, the sensor transmits a signal more frequently.
After each sensor has responded to a low frequency signal from the TPMS module, the sensor is assigned a position on the vehicle and is monitored in that position until the end of the current driving cycle.
After the vehicle has been parked for more than 15 minutes and driven at a speed of more than 20 km/h, the initiators turn on in turn for 6 seconds on all vehicles, except for vehicles for the North American market, and for 18 seconds on vehicles for the North American market, in the following order:
- Left front
- Pause 6 seconds (for the TPMS module to receive a response signal from the tire pressure sensor)
- Right front
- Pause 6 seconds
- Right rear
- Pause 6 seconds
- Left back
- Pause 6 seconds.
Each tire pressure sensor responds to the module in turn so that the module can determine the location of the sensors and begin the driving cycle. This process is repeated up to three times or less if the location of the sensors is already known to the module. This process is called "automatic location detection" and takes 7-8 minutes on North American vehicles and 3-4 minutes on all other vehicles. During this time, the tire pressure sensors transmit signals at regular intervals, which are 15 seconds for vehicles destined for the North American market and 5 seconds for all other vehicles. Thereafter, during the driving cycle, the pressure sensors transmit signals every 60 seconds, as well as when a change in tire pressure is detected, until the vehicle stops and the system enters the parking mode.
Once the wheel position is determined, the initiators stop firing until the vehicle has been stationary for 15 minutes. While the vehicle is moving, each tire pressure sensor transmits a signal at 1 minute intervals. This allows you to control tire pressure. There are two levels of warning: the yellow indicator lights up at a pressure drop of 25%, and a corresponding message appears on the instrument cluster message center display at a pressure drop of 35%. The message center display also provides additional information about the position of the flat tire.
Initiator
The initiators are located near the front side of the front wheel arches and next to the rear side of the rear wheel arches and are secured with two rivets. The TPMS system has four initiators. Each initiator has a connector with which it is connected to the body wiring harness.
The initiator is a passive low frequency transmitter. Each initiator supports the function of automatically detecting the position of the tire on the vehicle and transmits the corresponding data to the TPMs.
The TPMS module turns on each initiator in turn with low frequency pulses. The corresponding tire pressure sensor detects low frequency pulses and transmits an RF response signal containing its data. The TPMS module receives this data via the internal RF antenna. The module can then determine which sensor is transmitting data and set its position on the vehicle.
Tire pressure sensor
The TPMS system uses "active" tire pressure sensors installed on each wheel inside the tire. The sensor is attached to the wheel with a valve. The sensors transmit RF signals at 315 or 433 MHz, depending on market requirements.
Sensors periodically measure the pressure and temperature of the air in the tires. Pressure and temperature data are periodically sent to the vehicle's RF receiver.
Tire pressure sensors are self-contained devices and do not have external electrical connections.
To avoid damage to sensors, follow the recommendations in section "Tire change" of this chapter. If the sensor is replaced, also replace the nut, seal and washer and tighten the sensor mounting to the torque specified in the Repair Manual.
Each sensor's RF signal contains a unique identification code that the TPMS module can use to identify the tire on the vehicle. If the sensor is replaced with "working" wheel, the identification data of the new sensor will be acquired the first time you drive at 20 km/h for 15 minutes. If a new sensor is installed on the spare wheel, its identification data must be programmed into the TPMS module using T4, otherwise this wheel will not be monitored. The code is located on the label of the new wheel/tire assembly and is also printed on the packaging of each sensor.
In addition, you can program the spare wheel data by using it as a "working" within 15 minutes while driving at a speed of 20 km/h.
To conserve battery power, the tire pressure sensor transmits data at different intervals while stationary and while driving. Wheel speed at which transition from low data rate occurs (in the parking lot) to high (when moving) very small, which is important when driving slowly off-road.
TPMS switch
NOTE: The TPMS switch is not installed on vehicles for the North American market. Vehicles for the North American market do not have a desired pressure selection function.
The TPMS switch is a momentary button located on the center console switch panel next to the hazard warning switch.
The TPMS switch is used by the driver to set the vehicle's desired tire pressure for "normal load" And "increased load". The switch allows you to select one of two modes.
The face of the TPMS switch contains a status LED that informs the driver of the desired pressure mode selected - for "normal load" or "increased load". The LED is on when the mode is selected "normal load". The LED is off when the mode is selected "increased load".
The status LED has two lighting modes - day and night. The brightness of the LED is determined by the TPMS module based on data received from the vehicle's CAN bus.
The switch is used to switch modes. The ignition key must be in position II. If TPMS is in "normal load", pressing and holding the switch will change the required pressure values to the values corresponding to the mode "increased load". The LED will turn off and the message 'Tire Pressures High Load Condition' will flash on the instrument panel for 5 seconds (tire pressure mode for increased load). This mode will work until the driver turns it off.
To switch from mode "increased load" into mode "normal load" The ignition key must be in position II and the switch must be pressed and held. In this case, the required pressure values corresponding to the mode will be set "normal load". The switch LED will illuminate and the instrument panel will display the message 'Tire Pressures Normal condition' for 5 seconds (tire pressure mode for normal load).
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