Canada - Tires - Tire Pressure Warning System Diagnostic Tips

Bulletin
TSB2659

Issue Date
December 05, 2006

Market
Canada

Title
DIRECT TIRE PRESSURE WARNING SYSTEM DIAGNOSTIC TIPS

Component
GENERAL INFORMATION

Models
'04 - '07 Applicable Toyota

INTRODUCTION:

The Tire Pressure Warning System (TPWS) monitors the difference in tire pressure in all four or five tires (if the vehicle is equipped with a full-size spare tire) through radio wave signals from a tire pressure valve/sensor mounted in each wheel.

This bulletin provides an overview and diagnostic information for the direct-type TPWS.

APPLICABLE VEHICLES:
- 2004 -- 2007 model year 4Runner vehicles.
- 2005 -- 2006 model year Tundra vehicles.
- 2005 -- 2007 model year Sequoia vehicles.
- 2006 -- 2007 model year Prius, RAV4, and Tacoma vehicles.
- 2007 model year Avalon, Camry and Solara vehicles.






REQUIRED SSTs:






WARRANTY INFORMATION:

SUMMARY OF TPWS/ COMPONENT OPERATION:







The illustration is an example of the TPWS components location on 2004 -- 2007 model year 4Runner vehicles:

For exact location of each vehicle's TPWS components, refer to ETAS, applicable model and model year Repair Manual: Tire and Wheel (refer to component or parts location). For additional information on the TPWS components and operation, refer to ETAS, applicable model and model year New Car Features: Chassis and Drivetrain.

Tire Pressure Warning Valve/Sensor:
Each wheel (including the spare tire on certain vehicles) has a tire pressure warning valve/sensor integrated into the air valve with a unique ID number that measures the tire pressure and tire temperature and then transmits the information to the antenna/receiver mounted inside the vehicle through a radio wave signal. The unique ID number must be manually entered into the ECU using the Diagnostic Tester whenever the tire pressure warning valve/sensor is replaced or after a tire and wheel are exchanged.












Vehicles equipped with a tire pressure warning valve/sensor inside the spare tire are listed in the table:

NOTE:.
- All Japan built vehicles require the tire pressure warning valve/sensors to be activated (Wake-up) during Pre-Delivery Service (PDS).
- Each tire pressure warning valve/sensor is equipped with a lithium battery that has an average life span of 10 years.
- If a tire pressure warning valve/sensor is removed from the wheel, the grommet MUST be inspected and replaced if damaged.

Tire Pressure Warning System Antenna/Receiver:
The antenna/receiver receives each tire pressure, tire temperature, and the unique tire pressure warning valve/sensor ID numbers through radio wave signals from the tire pressure warning valve/sensors and then transmits the information to the TPWS ECU.

Tire Pressure Warning System ECU:
The ECU takes each tire pressure, tire temperature and unique tire pressure warning valve/sensor ID information from the antenna/receiver and compares it to the specified value, which was registered during PDS. If the information received does NOT match the specified value registered in the ECU, it will transmit a signal to illuminate the Tire Pressure Warning System Indicator Light located on the combination meter. If the ECU is replaced, it is necessary to manually enter the tire pressure valve/sensor ID numbers using the Diagnostic Tester.







Tire Pressure Warning System Indicator Light:
The Tire Pressure Warning System Indicator Light on the combination meter is illuminated or flashes continuously when the ECU senses that the tire pressure, tire temperature, and/or unique ID number does NOT match the specified value registered in the ECU.







Conditions for the Tire Pressure Warning System Indicator Light "ON" or "Flashing" are listed in the table:

Initialization/"SET" Switch:
When initializing the TPWS, the present tire pressure is set as the standard pressure (for example: 32 psi). The TPWS determines a decrease in air pressure by comparing the standard pressure to the tire inflation pressure received from the tire pressure warning valve/sensor.

Reasons for initializing the system include:
- When rotating tires that have different tire pressures in the front and rear.
- When changing or adjusting the tire pressure.
- When changing tire size or when tires are replaced.







The vehicles listed in the table are equipped with a Initialization/"SET" switch:

DIAGNOSTIC TESTER SETUP:







When diagnosing the TPWS with the Diagnostic Tester, it must be set up to read the tire pressures in "PSI -- Gauge" (psi -- g). Follow the screens from the Diagnostic Tester to convert the tire pressures to psi -- g.






SYSTEM CONCERNS & REPAIR METHODS:

REGISTRATION PROCEDURE:

Registration of tire pressure warning valve/sensor ID numbers:

1. Jump TC and CG at DLC3 Key ON Engine OFF for 30 seconds







2. Register the 7-digit IDs:
3. Confirm the actual tire pressure to the Diagnostic Tester Data List and set according to the tire inflation pressure indicated on the vehicle loading specification label.
4. Confirm that the Tire Pressure Warning System Indicator Light is OFF.
5. Push and hold the Initialization/"SET" switch (if equipped) until the Low TPWS Light blinks 3 times and then release the switch. Keep the ignition key ON for 5 minutes for the system to initialize.

The registration is complete.
















DIAGNOSTIC FLOW CHART:

NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.