Tire Pressure Warning System (For Sedan) System Description

Each tire pressure warning valve and transmitter is equipped with a tire pressure sensor and a transmitter and is installed in each tire wheel. The sensor measures the tire pressure. The measured value and transmitter ID are transmitted to the tire pressure warning antenna and receiver on the body as radio waves and then sent to the tire pressure warning ECU from the tire pressure warning antenna and receiver. If the transmitter ID has already been registered, the ECU compares the measured air pressure value with the standard value. When the value is less than the standard value registered in the tire pressure warning ECU, the warning light on the combination meter turns on.

After the ignition switch is turned to ON, the tire pressure warning light turns on for 3 seconds and then turns off.

HINT:

If the warning light does not turn on for 3 seconds, troubleshoot the pressure warning light circuit.

When the tire pressure warning light does not go off, or when it turns on during driving, check the tire pressure. If the tire pressure warning light turns on within several hours of adjusting the tire pressure, the tire may have a slow air leak.

Under the following conditions, the system may not function properly.

1. Facilities or devices that use similar radio frequencies are located in the vicinity of the vehicle.
   
2. A radio device of similar frequency is used in the vehicle.
   
3. A large amount of snow or ice is stuck to the vehicle, especially onto the wheels and around the wheel houses.
   
4. The battery of the sensor has been depleted.
   
5. Tires without a tire pressure warning valve and transmitter are used.
   
6. Tire chains are used.
   
7. If any wheels other than the specified ones are used, the system may not function properly because interference may prevent the radio waves from being correctly transmitted from the tire pressure warning valve and transmitter.
   
8. A type of film that affects radio waves is attached to the windows.
   
9. Depending on the tire type, the system may not function properly even if the specified wheels are used.
   
10. The tire pressure is abnormally high (absolute pressure: 600 kPa (6 kgf/cm², 87 psi) or more; relative pressure: 500 kPa (5 kgf/cm², 72.5 psi) or more).
    

The average usage life of the grommet of the tire pressure warning valve and transmitter is approximately 10 years, at which time it must be replaced.
If a tire pressure warning valve and transmitter is removed from a wheel, replace the grommets.

After removing and installing the ECU or a sensor, check for a diagnostic trouble code and verify that it is a normal code.