Toyota Tundra. Manual — part 2478

Fig. 18: Identifying Main Body ECU And Automatic Light Control Sensor Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE AUTOMATIC LIGHT CONTROL SENSOR (see REMOVAL )

HEADLIGHT DIMMER SWITCH CIRCUIT

DESCRIPTION

The turn signal flasher receives a turn signal light information signal from the headlight dimmer switch.

Tester Connection

Condition Specified Condition

J3-20 (CLTB) - K19-6 (CLTB)

Always

Below 1 ohms

J3-19 (CLTS) - K19-5 (CLTS)

J3-18 (CLTE) - K19-3 (CLTE)

J3-20 (CLTB) - Body ground

Always

10 kohms or higher

J3-19 (CLTS) - Body ground

J3-18 (CLTE) - Body ground

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

WIRING DIAGRAM

Fig. 19: Identifying Headlight Dimmer Switch - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. INSPECT HEADLIGHT DIMMER SWITCH (TURN SIGNAL SWITCH)

a. Remove the headlight dimmer switch (see REMOVAL ).

Fig. 20: Identifying Headlight Dimmer Switch Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

HEADLIGHT DIMMER SWITCH (TURN SIGNAL SWITCH)

NG: REPLACE HEADLIGHT DIMMER SWITCH (see REMOVAL )

OK: Go to next step

2. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - TURN SIGNAL

FLASHER AND BODY GROUND)

a. Disconnect the J10 switch connector.

b. Disconnect the J29 relay connector.

Fig. 21: Identifying Headlight Dimmer Switch And Turn Signal Flasher Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

HEADLIGHT DIMMER SWITCH - TURN SIGNAL FLASHER AND BODY GROUND

Tester Connection

Switch Condition

Specified Condition

13 (TR) - 12 (EL)

Turn signal switch right turn

Below 1 ohms

Turn signal switch left turn 10 kohms or higher

15 (TL) - 12 (EL)

Turn signal switch left turn

Below 1 ohms

Turn signal switch right turn 10 kohms or higher

Tester Connection

Condition Specified Condition

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

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

DRL RELAY CIRCUIT

DESCRIPTION

The daytime running light relay is built into the turn signal flasher.

When the daytime running light relay receives the ignition switch ON signal from the main body ECU, the turn
signal flasher illuminates the turn signal light. When the daytime running light relay receives the headlight
dimmer switch signal, the turn signal flasher turns off the turn signal light.

WIRING DIAGRAM

Fig. 22: Identifying DRL Relay - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK HARNESS AND CONNECTOR (TURN SIGNAL FLASHER - MAIN BODY ECU)

a. Disconnect the J29 relay connector.

b. Disconnect the J3 ECU connector.

J10-13 (TR) - J29-7 (ER)

Always

Below 1 ohms

J10-15 (TL) - J29-6 (EL)

J10-12 (EL) - Body ground

J10-13 (TR) - Body ground

Always

10 kohms or higher

J10-15 (TL) - Body ground

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra