Toyota Tundra. Manual — part 2486

Fig. 53: Identifying Main Body ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard voltage

MAIN BODY ECU - BATTERY

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

5. CHECK HARNESS AND CONNECTOR (TAILLIGHT - MAIN BODY ECU)

Fig. 54: Identifying Taillight And Main Body ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Tester Connection Condition Specified Condition

DA-1 - Body ground Always

11 to 14 V

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

a. Disconnect the DB ECU connector.

b. for LH:

1. Disconnect the R5 taillight connector.

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

Standard resistance

TAILLIGHT - MAIN BODY ECU LH

c. for RH:

1. Disconnect the R4 taillight connector.

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

Standard resistance

TAILLIGHT - MAIN BODY ECU RH

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE MAIN BODY ECU

LIGHT CONTROL SWITCH CIRCUIT

DESCRIPTION

The main body ECU receives light control switch, dimmer switch and front fog light switch information signals
from the headlight dimmer switch.

WIRING DIAGRAM

Tester Connection

Condition Specified Condition

R5-4 (TL) - DB-8

Always

Below 1 ohms

R5-4 (TL) - Body ground Always

10 kohms or higher

Tester Connection

Condition Specified Condition

R4-4 (TL) - DB-8

Always

Below 1 ohms

R4-4 (TL) - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Fig. 55: Identifying Light Control Switch - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. READ VALUE OF TECHSTREAM (HEADLIGHT DIMMER SWITCH)

a. Operate the Techstream according to the display and select the "DATA LIST" or "Data List".

Techstream

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Main Body

MAIN BODY - TECHSTREAM DATA LIST CHART

OK: When combination light switch operation is performed, the result will be the same
as above.

NG: Go to step 2

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

2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

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

Tester

Display

Measurement Item/Range

Normal Condition

Diagnostic

Note

Dimmer SW

Dimmer switch signal / ON or
OFF

ON: Dimmer switch ON
OFF: Dimmer switch OFF

-

High Flasher

SW

Passing light switch signal / ON
or OFF

ON: Passing light switch
ON
OFF: Passing light switch
OFF

-

F Fof Light

SW

Front fog light switch signal / ON
or OFF

ON: Front fog light switch
ON
OFF: Front fog light
switch OFF

-

Auto Light

SW

Auto light switch signal / ON or
OFF

ON: Auto light switch ON
OFF: Auto light switch
OFF

-

Head Light

SW

Headlight switch signal / ON or
OFF

ON: Headlight switch ON
OFF: Headlight switch
OFF

-

Tail Light SW

Taillight switch signal / ON or
OFF

ON: Taillight switch ON
OFF: Taillight switch
OFF

-

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra