Toyota Tundra. Manual — part 2489

Fig. 64: Identifying Main Body ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. Using a service wire, connect DB-18 (HRLY) on the wire harness side and body ground.

c. Check that the headlight low beam illuminates.

OK: Headlight low beam illuminates.

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

OK: REPLACE MAIN BODY ECU

DOOR COURTESY SWITCH CIRCUIT

DESCRIPTION

The main body ECU receives a door open/closed signal from each door courtesy light switch.

WIRING DIAGRAM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Fig. 65: Identifying Door Courtesy Switch - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. READ VALUE OF TECHSTREAM (DOOR COURTESY LIGHT SWITCH)

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

Techstream

Main Body

MAIN BODY - TECHSTREAM DATA LIST CHART

Tester

Display

Measurement Item/Range

Normal Condition

Diagnostic

Note

D Dor Cty

SW

Front door courtesy light switch
LH signal / ON or OFF

ON: Front door courtesy
light switch LH ON
OFF: Front door courtesy
light switch LH OFF

-

P Dor Cty

SW

Front door courtesy light switch
RH signal / ON or OFF

ON: Front door courtesy
light switch RH ON
OFF: Front door courtesy
light switch RH OFF

-

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Result

RESULT CHART

B: Go to step 2

C: Go to step 4

D: Go to step 6

E: Go to step 8

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

2. INSPECT FRONT DOOR COURTESY LIGHT SWITCH LH

a. Remove the front door courtesy light switch LH (see REMOVAL ).

RL Dor Cty

SW

Rear door courtesy light switch LH
signal / ON or OFF

ON: Rear door courtesy light
switch LH ON
OFF: Rear door courtesy
light switch LH OFF

-

RR Dor Cty

SW

Rear door courtesy light switch RH
signal / ON or OFF

ON: Rear door courtesy light
switch RH ON
OFF: Rear door courtesy
light switch RH OFF

-

Result

Proceed to

OK

A

NG (Front door courtesy light switch LH does not operate)

B

NG (Front door courtesy light switch RH does not operate)

C

NG (Rear door courtesy light switch LH does not operate)

D

NG (Rear door courtesy light switch RH does not operate)

E

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra

Fig. 66: Identifying Front Door Courtesy Light Switch - LH
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

Standard resistance

FRONT DOOR COURTESY LIGHT SWITCH LH

NG: REPLACE FRONT DOOR COURTESY LIGHT SWITCH LH (see REMOVAL )

OK: Go to next step

3. CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH LH

MAIN BODY ECU)

a. Disconnect the P5 switch connector.

b. Disconnect the J4 ECU connector.

Tester Connection Switch Condition Specified Condition

1 - Body ground

Not pushed

Below 1 ohms

Pushed

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Lighting - Tundra