Toyota Tundra. Manual — part 375

Fig. 34: Checking Harness And Connector (Transponder Key ECU - Security Indicator
Light)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE ACCESSORY METER (SECURITY INDICATOR LIGHT) (See REMOVAL )

ECU POWER SOURCE CIRCUIT

DESCRIPTION

This circuit provides power to operate the transponder key ECU.

WIRING DIAGRAM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Fig. 35: ECU Power Source - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. INSPECT FUSE (1MB, IGN)

a. Remove the 1MB fuse and IGN fuse from the engine room relay block.

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

Standard resistance

FUSE (1MB, IGN) TESTER CONNECTION SPECIFIED CONDITION CHART

NG: REPLACE FUSE

OK: Go to Next Step

2. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY

GROUND)

a. Disconnect the J26 ECU connector.

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

Tester Connection Condition Specified Condition

IMB fuse

Always

Below 1 ohms

IGN fuse

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Standard resistance

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY
GROUND) TESTER CONNECTION SPECIFIED CONDITION CHART RESISTANCE

Standard voltage

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY
GROUND) TESTER CONNECTION SPECIFIED CONDITION CHART VOLTAGE

Fig. 36: Identifying J26 ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE

DIAGNOSIS CIRCUIT

DESCRIPTION

This circuit is used to read the DTCs that are output from the transponder key ECU with the Techstream.

WIRING DIAGRAM

Tester Connection

Condition Specified Condition

J26-16 (GND) - Body ground Always

Below 1 ohms

Tester Connection

Switch Condition Specified Condition

J26-1 (+B) - Body ground

Always

11 to 14 V

J26-2 (IG) - Body ground

Ignition switch OFF

Below 1 V

Ignition switch ON

11 to 14 V

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Fig. 37: Diagnosis Circuit - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - DLC3)

a. Disconnect the J26 ECU connector.

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

Standard resistance

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - DLC3) TESTER
CONNECTION SPECIFIED CONDITION CHART

Tester Connection

Condition Specified Condition

J26-9(D) - J17-7(SIL)

Always

Below 1 ohms

J26-9(D) or J17-7(SIL)- Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra