System Description

System Diagram:

SYSTEM DESCRIPTION

1. DESCRIPTION OF SYSTEM

a. A tire pressure monitor valve sub-assembly equipped with tire pressure sensor, transmitter is installed in a tire wheel assembly. The sensor measures the tire pressure and the measured value and transmitter ID are transmitted to the tire pressure monitor receiver assembly on the body as radio waves and then sent to the tire pressure monitor ECU from the tire pressure monitor receiver. If the transmitter ID has already been registered, the ECU compares the measured tire pressure value and the warning threshold pressure value. When the value is less than the warning threshold pressure value registered in the tire pressure monitor ECU, the tire pressure warning lamp on the combination meter comes on.

2. WHEN TIRE PRESSURE WARNING LAMP IS LIT

a. When the tire pressure warning lamp does not go off, or when it comes on during driving, check tire pressure. If the tire pressure warning lamp comes on within several hours after adjusting the tire pressure, the tire may have a slow air leak. If the tire pressure warning lamp comes on even after adjusting the tire pressure, selection of the tire pressure warning switch "MAIN" / "2nd" may be incorrect.

b. Under the following conditions, the system may not function properly.
- The areas, facilities or devices that use similar radio wave frequencies are located in the vicinity of the vehicle.
- A radio device of similar frequency is used near the vehicle.
- A lot of snow or ice is stuck to the vehicle, especially the wheels and around the wheel houses.
- The battery of the sensor has been depleted.
- The tires without tire pressure monitor valve sub-assembly are used.
- Tire chains are used.
- Wheels other than manufacturer spec LEXUS GX470 wheels are used.
- Although the tires with tire pressure sensors are used, another tire set has been selected by the tire pressure warning switch.

HINT:
- If any other wheels than the specified ones are used, the system may not function properly because the radio waves are differently transmitted from the tire pressure sensor.
- Depending on the tire type, the system may not function properly even though the specified wheels are used.

c. The average life of the grommet of the tire pressure monitor valve sub-assembly is approximately 5 years, at which time it must be replaced.
Re-tighten the valve nut if the valve is air leaking, is less than 5 years old and there is no problem with grommets.
Torque: 4 N.m (41 kgf.cm, 36 in.lbf)

d. After removing and installing the ECU or a sensor, output a diagnosis code and check that it is a normal system code.

Function Of Components:

3. FUNCTION OF COMPONENTS