Tire Monitor System - Initialization Procedure

PRE-DELIVERY SERVICE
PD006-04

Title:
INITIALIZATION OF TIRE PRESSURE
WARNING SYSTEM

Models:
'05 RX 330

October 29, 2004

Introduction

While the vehicle is in motion, the Tire Pressure Warning System (TPWS) monitors the wheel speed signals that are output by the speed sensors for the brake control system. The system uses the resonance frequency method and the relative wheel speed method to detect low tire pressure in one or more of the tires. The resonance frequency method detects a change in the resonance of the tires that is caused by a low tire pressure based on the total value of the wheel speed signals that are output by the four speed sensors. The relative wheel speed method utilizes the changes in the wheel speeds that occur when the actual radius of a tire decreases due to a low tire pressure. These two methods refer to the normal tire pressure as the standard value when initializing.

To operate the Tire Pressure Warning System under normal conditions, the TPWS ECU must be initialized with the tires at the specified tire inflation pressure.

Tire pressure is set high at the assembly plant for transport and storage to prevent tire flat spots. Therefore, after adjusting all the tires to the standard air pressure, please perform initialization of the TPWS ECU at your dealership prior to delivery.

Applicable Vehicles

2005 model year RX 330 vehicles.





Warranty Information

Initialization Procedure





1. Adjust all tires to the standard air pressure, as indicated on the tire pressure label on the vehicle.





2. Turn the ignition switch to the "ON" position with the vehicle stopped. Check that the low tire pressure warning light blinks (twice per second).





3. Press the tire pressure warning reset switch for 3 seconds until the low tire pressure warning light blinks 3 times in 6 seconds (one blink per two seconds). After that, make sure the tire pressure warning light goes off.

NOTE:
If the low tire pressure warning light doesn't blink, release the switch once and press the tire pressure warning reset switch again.

REFERENCE:

While TPWS initialization is in progress, the tire pressure is not being monitored.

Please explain to the customer during vehicle delivery that initialization of the Tire Pressure Warning System will be completed after driving the vehicle for 30 to 60 minutes and that the tire pressure is not monitored before the completion of the initialization.

NOTE:
If the low tire pressure warning light begins to blink (twice per second) while driving, repeat the process above beginning with step 2.