Canada - Tire Monitor System - Initialization of TPMS
BulletinTSB2052R
Issue Date
October 27, 2004
Title
INITIALIZATION OF TIRE PRESSURE WARNING SYSTEM (TPWS)
Component
GENERAL INFORMATION
Models
'05 - '06 RX 330
TSB REVISION NOTICE:
- August 25, 2005: 2006 model year has been added to Applicable Vehicles.
- January 19, 2004: Text has been revised in #3 of the Initialization Procedure.
The previous TSB should be discarded.
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 - 2006 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 initialization 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.
The TPWS ECU will start to record vehicle data once the initialization process has started. The data collection process and initialization completion will depend on the vehicle owner's driving patterns, habits, and trip duration. Once the data collection process is complete, the accuracy of tire pressure detection will be increased.
NOTE:
If the low tire pressure warning light begins to blink (twice per second) while driving, repeat the process above in step 2.