Tire Monitoring System: Description and Operation

TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: SYSTEM DESCRIPTION

SYSTEM DESCRIPTION

1. DESCRIPTION OF SYSTEM
(a) Each tire pressure warning valve and transmitter is equipped with a tire pressure sensor and 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 tire 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.





2. INITIAL CHECK





(a) After the ignition switch is turned 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.





3. WHEN TIRE PRESSURE WARNING LIGHT IS LIT
(a) 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.
(b) The system will not operate under the following conditions:
HINT: When the problem is resolved, the system will operate properly.
- Tires without a tire pressure warning valve and transmitter are used.
- When a tire pressure warning valve and transmitter ID is not registered in the ECU.
- The tire pressure is abnormally high (absolute pressure: 600 kPa (6.1 kgf/cm2, 87 psi) or higher: relative pressure: 500 kPa (5.1 kgf/cm2, 73 psi) or higher).
- The battery of the tire pressure warning valve and transmitter has been depleted (battery life: 10 years).
- The tire pressure warning select switch is set to a different tire setting.

(c) The system may not operate under the following conditions:
HINT: When the problem is resolved, the system will operate properly.
- Facilities or devices that use similar radio frequencies are located in the vicinity of the vehicle.
- A radio device of similar frequency is used in the vehicle.
- A type of film that affects radio waves is attached to the windows.
- A large amount of snow or ice is stuck to the vehicle, especially onto the wheels and around the wheel houses.
- 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.
- Tire chains are used.
- A large metallic object which can interfere with signal reception is put in the luggage room.
- When the spare tire is not within the receivable range of the tire pressure warning antenna and receiver, the tire pressure warning antenna and receiver may not receive a signal because the spare tire is fixed in place. Accordingly, the system may not function properly. If there is a possibility that the tire pressure warning system does not receive a signal from the spare tire, rotate the tire 90 to 270°.

(d) If a tire pressure warning valve and transmitter is removed from a wheel, replace the grommet.
(e) After removing and installing the ECU or a sensor, check for a diagnostic trouble code and verify that it is a normal code.
4. FUNCTION OF COMPONENTS






5. TIRE PRESSURE WARNING SELECT SWITCH

- This switch is installed at the base of the instrument panel on the front driver seat side.
- 2 sets of transmitter IDs can be registered into the tire pressure warning ECU, and then the 2 sets of transmitter IDs can be selected using the tire pressure warning select switch. Consequently, there is no need to register the transmitter IDs again each time a tire set is changed.
- Make sure ID registration is performed by your car dealer.

SYSTEM DIAGRAM




HINT: The tire pressure warning valve and transmitter sends information on the temperature inside the tire, the ID, and the tire pressure.