Toyota Tundra. Manual — part 2778

Fig. 35: Tire Pressure Warning Light - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (COMBINATION METER)

a. Turn the ignition switch off.

b. Connect the Techstream to the DLC3.

c. Turn the ignition switch to ON and the Techstream on.

d. Enter the following menus: Body/Combination Meter/Active Test.

e. Check the condition of the tire pressure warning light by operating the tester.

Combination Meter

DIAGNOSTIC NOTE TABLE

OK: The warning light turns on/off when operating the Techstream.

NG: GO TO METER/GAUGE SYSTEM (See HOW TO PROCEED WITH
TROUBLESHOOTING )

NOTE:



When replacing the tire pressure warning ECU, read the transmitter IDs
stored in the old ECU using the Techstream and write them down before
removal.



It is necessary to perform INITIALIZATION after REGISTRATION of the
transmitter IDs into the tire pressure warning ECU after the ECU and/or tire
pressure warning valve and transmitter has been replaced.

Tester Display

Test Part

Control

Range

Diagnostic

Note

Indicat. Tire Pressure Warning

System

Tire Pressure Warning Light

illuminates

ON or OFF

-

2009 Toyota Tundra

2009 SUSPENSION Tire & Wheel - Tundra

OK: Go to next step

2. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECU)

a. Disconnect the J31 ECU connector.

b. Disconnect the J28 meter connector.

c. Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Fig. 36: Identifying J31 ECU Connector & J28 Meter Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK ECU POWER SOURCE CIRCUIT (See ECU POWER SOURCE CIRCUIT )

ECU POWER SOURCE CIRCUIT

DESCRIPTION

This is the power source for the tire pressure warning ECU.

Tester Connection

Condition Specified Condition

J31-5 (IND) - J28-7 (TIRE) Always

Below 1 ohms

J31-5 (IND) - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 SUSPENSION Tire & Wheel - Tundra

WIRING DIAGRAM

Fig. 37: ECU Power Source - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. INSPECT FUSE (ECU-IG)

a. Remove the ECU-IG No. 1 fuse from the main body ECU.

b. Measure the resistance according to the value(s) in the table below.

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

NOTE:



When replacing the tire pressure warning ECU, read the transmitter IDs
stored in the old ECU using the Techstream and write them down before
removal.



It is necessary to perform INITIALIZATION after REGISTRATION of the
transmitter IDs into the tire pressure warning ECU after the ECU and/or tire
pressure warning valve and transmitter has been replaced.

Tester Connection Condition Specified Condition

ECU-IG No. 1 fuse Always

Below 1 ohms

2009 Toyota Tundra

2009 SUSPENSION Tire & Wheel - Tundra

NG: Go to step 3

OK: Go to next step

2. CHECK HARNESS AND CONNECTOR (ECU - BATTERY AND BODY GROUND)

a. Disconnect the J31 ECU connector.

b. Measure the voltage and resistance according to the value(s) in the table below.

Standard Voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Fig. 38: Identifying J31 ECU Connector (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : REPLACE TIRE PRESSURE WARNING ECU (See REMOVAL )

3. CHECK HARNESS AND CONNECTOR (ECU - BATTERY)

a. Disconnect the J31 ECU connector.

b. Measure the resistance according to the value(s) in the table below.

Tester Connection

Switch Condition Specified Condition

J31-7 (IG) - Body ground Ignition switch ON

11 to 14 V

Tester Connection

Condition Specified Condition

J31-9 (GND) - Body ground Always

Below 1 ohms

2009 Toyota Tundra

2009 SUSPENSION Tire & Wheel - Tundra