Toyota Tundra. Manual — part 2480

Fig. 27: Identifying Headlight Connector Terminals - RH
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard voltage

HEADLIGHT HIGH BULB - BATTERY RH

NG: Go to step 4

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT HIGH BULB -
BODY GROUND)

4. INSPECT HEADLIGHT DIMMER RELAY (DIM)

a. Remove the headlight dimmer relay from the engine room relay block.

Tester

Connection

Switch Condition

Specified

Condition

A9-2 - Body

ground

Light control switch HEAD, dimmer switch High

11 to 14 V

Light control switch HEAD, dimmer switch except

High

Below 1 V

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Fig. 28: Identifying Headlight Dimmer Relay (DIM) 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

HEADLIGHT DIMMER RELAY (DIM)

NG: REPLACE HEADLIGHT DIMMER RELAY

OK: Go to next step

5. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - BATTERY)

a. Remove the headlight dimmer relay from the engine room relay block.

Fig. 29: Identifying Headlight Dimmer Relay (DIM) 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

HEADLIGHT DIMMER RELAY - BATTERY

Tester Connection

Condition

Specified Condition

3 - 5

When battery voltage is not applied to terminals land 2 10 kohms or higher

When battery voltage is applied to terminals 1 and 2

Below 1 ohms

Tester Connection

Switch Condition

Specified

Condition

Headlight dimmer relay terminal 1 -

Body ground

Light control switch HEAD, dimmer

switch Low

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

6. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - HEADLIGHT

HIGH BULB)

Fig. 30: Identifying Headlight Dimmer Relay And Headlight High Bulb Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

a. Remove the headlight dimmer relay from the engine room relay block.

b. for LH:

1. Disconnect the A8 headlight connector.

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

Standard resistance

HEADLIGHT DIMMER RELAY - HEADLIGHT HIGH BULB LH

c. for RH:

1. Disconnect the A9 headlight connector.

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

Standard resistance

HEADLIGHT DIMMER RELAY - HEADLIGHT HIGH BULB RH

Headlight dimmer relay terminal 3 -

Body ground

Light control switch HEAD, dimmer

switch Low

11 to 14 V

Tester Connection

Condition Specified Condition

Headlight dimmer relay terminal 5 - A8-2

Always

Below 1 ohms

Headlight dimmer relay terminal 5 - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

7. CHECK HEADLIGHT (HIGH BEAM)

a. Disconnect the DB ECU connector.

Fig. 31: Identifying Main Body ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. Using a service wire, connect DB-19 (DIM) on the wire harness side and body ground.

c. Check that the headlight high beam illuminates.

OK: Headlight high beam illuminates.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT DIMMER RELAY -
MAIN BODY ECU)

OK: REPLACE MAIN BODY ECU

FRONT FOG LIGHT CIRCUIT

DESCRIPTION

The main body ECU receives a front fog light switch information signal from the light control switch (front fog
switch), and illuminates the front fog lights.

Tester Connection

Condition Specified Condition

Headlight dimmer relay terminal 5 - A9-2

Always

Below 1 ohms

Headlight dimmer relay terminal 5 - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra