Tire Pressure Monitor - Sensor Registration/Initializing
PRODUCT GENERAL INFORMATIONPG007-05
August 1, 2005
Introduction
A direct Tire Pressure Warning System (TPWS) is now standard equipment on all 2006 model year GS 300 and GS 430 vehicles.
A tire pressure sensor (or tire pressure monitor) is attached to each wheel directly sensing the air pressure of each tire. The Tire Pressure Warning System detects the pressure of each tire (not including the space saver spare tire) and illuminates a tire pressure warning light (!) to inform the driver of low tire pressure.
A "SET" switch has also been added to the GS 300 and GS 430 to set the tires threshold pressure (the lowest tire pressure allowed before the warning light comes on) so that different tire and wheel pressure requirements can be accommodated.
This TSB will explain how to:
^ Locate the TPWS sensor ID numbers.
^ Register TPWS sensor ID numbers using the Lexus Diagnostic Tester.
^ Utilize the "SET" switch to initialize the threshold detection pressure.
Applicable Vehicles
^ 2006 model year GS 300 and GS 430 vehicles.
Required SSTs
NOTE:
Additional Diagnostic Tester Kits, CAN Interface Modules, Program Cards, or other SSTs may be ordered by calling SPX-OTC at 1-800-933-8335.
Warranty Information
Tire Sensor ID Numbers
Each tire pressure sensor has a unique ID number (refer to Figure 2 shown). These ID numbers must match the numbers registered in the TPWS ECU. In the event that one of the following services are performed, the ID numbers must be manually re-recorded in the TPWS ECU to ensure proper operation:
^ Replacing a tire and wheel from one vehicle to another.
^ Replacing the tire pressure monitor valve sub-assembly (tire pressure sensor).
^ Replacing the tire pressure monitor ECU.
NOTE:
^ To help in the ID number retrieval process, it is recommended that you record the ID numbers on a separate document (Repair Order, PDS Checksheet, etc.) so they can be easily accessed for future use.
^ In the event that the ID numbers were not previously recorded or if using the Diagnostic Tester, the current registered ID numbers show all zeroes or # signs in the Data List. It will be necessary to remove each tire from the wheel to physically locate and record the sensor ID number imprinted on each sensor. Refer to step 1 under "Locating the Sensor IS Numbers".
^ When the ECU does NOT respond due to initialization being performed with the wrong ID registered, connect terminals 13 (TC) and 4 (CG) of the DLC3 to restore the ECU.
Locating the Sensor ID Numbers
Using the Diagnostic Tester, follow the screen prints shown to access and confirm the currently registered tire pressure sensor ID numbers.
On screen "G" above, record the sensor ID numbers listed in the REGIT ID 1 - 4 so they can be manually re-entered during the registration process. The sensor ID numbers listed in the Data List REGIT ID 1 - 4 are the actual sensor ID numbers registered in the TPWS ECU (these sensor ID numbers may or may not be the correct sensor ID numbers for the tires currently on the vehicle).
NOTE:
It is important that each of these Sensor ID numbers be recorded on a separate document because once you enter the registration ID number, they will be erased. In addition, if you replace one or more sensors, the sensor ID number printed on the new sensor needs to be recorded as well.
You will confirm the sensor ID numbers are for this vehicle during the registration process. If they are not correct, you will have to locate the correct sensor ID numbers on each tire and wheel assembly to complete the registration process. Refer to page 4 for instruction on how to locate the sensor ID numbers.
If the REGIT IDs display all zeros or # signs, that means there are no current sensor ID numbers registered in the system. You must physically locate the sensor ID number on each sensor before beginning the registration process. Refer to "Locating the Sensor ID Numbers" for instruction on how to locate sensor numbers. Once you have the sensor ID numbers for all 4 tires, proceed to the Tire Pressure ID Registration Procedure".
Follow the procedure below to locate the tire pressure sensor ID number on each sensor.
1. Deflate tire and break the top bead.
CAUTION:
Extreme caution must be used to ensure that the tire removal arm does not contact the tire pressure sensor while attempting to break the bead on the rim.
2. Depress the tire enough to inspect the tire pressure sensor.
NOTE:
It may be necessary to carefully remove the tire from the rim to inspect for this ID.
3. On the front of the sensor, there is a 7-digit ID number as shown in Figure 2.
Write this number down for future reference (it will be needed for input using the Diagnostic Tester).
4. Reseat the tire back to the wheel and set the tire pressure of all wheels to the specified value.
5. Remount the tire and wheel assembly to the vehicle.
6. Torque all wheels to the vehicle according to the following torque specification. For more information, refer to the Technical Information System (TIS), 2006 model year GS 300 or GS 430 Repair Manual: Tire And Wheel: Tire Pressure Monitor Valve: Components, Replacement.
Torque: 103 N.m (1050 kgf.cm, 76 ft.lbf)
7. Repeat other tire/match assemblies as necessary.
8. Go to the Tire Pressure ID Registration Procedure".
Tire Pressure ID Registration Procedure
1. Connect the Diagnostic Tester to DLC3.
2. Turn the ignition switch to the "ON" position. Follow the screen flow shown.
3. View the Lexus Diagnostic Tester Data List and ensure that all tires are reading tire pressure and temperature correctly (this could take up to 5 minutes).
NOTE:
^ If the sensor code does not read correctly within 5 minutes, you will need to locate the actual code on the TPWS tire sensor (refer to "Locating the Sensor ID Numbers").
^ It is extremely critical that the Main/2nd select switch is set to "MAIN" for the main tire set and "2ND" for the 2nd tire set. You will experience the incorrect ID number on the Data List if the select switch is in the incorrect position.
4. Set the threshold pressure. Refer to "Initializing Threshold Detection Pressure" below.
Set Switch Purpose and Function
A "SET" switch has been added to the GS 300 and GS 430 to set threshold detection pressure of the tires. Due to the required pressures of different wheel and tire combinations, it is necessary to perform this procedure under the following conditions.
^ New vehicle delivery
^ Tire rotation
^ Tire replacement
^ Tire pressure sensor replacement
^ Tire pressure monitor ECU replacement
NOTE:
Refer to driver's door jam for specific tire pressure settings.
Initializing Threshold Detection Pressure
1. Set the tire air pressure for all wheels to the specified value. Refer to the driver's door jam for specific tire pressure settings.
2. Press and hold the tire pressure warning "SET" switch for 3 seconds or more with the ignition switch "ON". After depressing the "SET" switch for 3 seconds or more, the tire pressure warning lamp will blink 3 times (1 second ON, 1 second OFF) and with the engine ON, "Pressure Initial" will appear on the multi-information display.
Perform system initialization when the vehicle tires are cold (driven less than 1 mile [1.6 km] after parked for 3 hours or more) and the tire pressure is adjusted to the specified value.
WARM TIRE NOTE:
If the tires are warm at the time of initialization, lower the tire pressure to the recommended specification on the driver's door jamb. Initialize the system utilizing the "SET" switch. When the light stops blinking, add 2.9 to 4.4 psi (0.2 to 0.3 kg/cm2, 20 to 30 kPa) back to the tire. This will ensure that when the tires are cold, they will NOT drop below specification.
NOTE:
^ Threshold detection pressure set due to initialization can be checked in INIT THRESHOLD 1 to 4 in the intelligent tester.
^ For further details of the Tire Pressure Warning System and functions of the SET switch, refer to TIS, 2006 model year GS 300 or GS 430 New Car Features Manual: Chassis and Drive train: Tire & Wheel.