Toyota Tundra. Manual — part 344

A: REPLACE MAIN BODY ECU

NO ANSWER-BACK

DESCRIPTION

In some cases, wireless door lock control functions are normal but the hazard warning lights and/or wireless
door lock buzzer answer-back function(s) do not operate. In such cases, the main body ECU's hazard warning
lights and wireless door lock buzzer signal outputs may be malfunctioning.

WIRING DIAGRAM

Fig. 65: Wireless Door Lock Control - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

1. CHECK WIRELESS DOOR LOCK CONTROL FUNCTION

a. Check the wireless door lock control functions by operating the transmitter switch.

Result

WIRELESS DOOR LOCK CONTROL FUNCTION RESULT REFERENCE

NOTE:

Troubleshooting should be started after confirming that the customize status of
the answer-back function has been switched ON.

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Door Lock - Tundra

B: Go to step 3

C: Go to ONLY WIRELESS CONTROL FUNCTION IS INOPERATIVE

A: Go to next step

2. PERFORM ACTIVE TEST BY TECHSTREAM (TURN SIGNAL FLASHER RELAY)

a. Select the Active Test, use the Techstream to generate a control command, and then check that the

hazard warning lights flash.

Techstream

Main body

TECHSTREAM DATA LIST - MAIN BODY

OK: Hazard warning lights turn ON or OFF.

NG: Go to LIGHTING SYSTEM (See HOW TO PROCEED WITH TROUBLESHOOTING )

OK: REPLACE MAIN BODY ECU

3. PERFORM ACTIVE TEST BY TECHSTREAM (WIRELESS DOOR LOCK BUZZER)

a. Select the Active Test, use the Techstream to generate a control command, and then check that the

wireless buzzer operates normally.

Techstream

Main body

TECHSTREAM ACTIVE TEST - MAIN BODY

OK: Wireless buzzer turns ON or OFF.

NG: Go to step 4

Result

Proceed

to

Wireless door lock functions are normal but hazard warning light answer-back does not
occur

A

Wireless door lock functions are normal but wireless door lock buzzer answer-back
does not occur

B

Doors cannot be locked and unlocked with transmitter

C

Tester Display Test Part Control Range Diagnostic Note

Hazard

Flasher relay

ON or OFF

-

Tester Display

Test Part

Control Range Diagnostic Note

Wireless Buzzer Sounds wireless buzzer

ON or OFF

-

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Door Lock - Tundra

OK: REPLACE MAIN BODY ECU

4. CHECK HARNESS AND CONNECTOR (WIRELESS DOOR LOCK BUZZER - MAIN BODY

ECU AND BODY GROUND)

a. Disconnect the A34 buzzer connector.

b. Disconnect the J1 ECU connector.

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

Standard resistance

HARNESS AND CONNECTOR (WIRELESS DOOR LOCK BUZZER - MAIN BODY ECU
AND BODY GROUND) STANDARD RESISTANCE SPECIFICATION

Fig. 66: Identifying A34 Buzzer And J1 ECU Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

5. CHECK WIRELESS DOOR LOCK BUZZER (OPERATION)

a. Temporarily replace the wireless door lock buzzer with a new or normally functioning one (see

Tester Connection

Condition Specified Condition

A34-1 - J1-7 (BZR)

Always

Below 1 ohms

A34-2 - Body ground

A34-1 or J1-7 (BZR) - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Door Lock - Tundra

WIRELESS DOOR LOCK BUZZER ).

b. Check that the buzzer sounds when using the transmitter LOCK and UNLOCK switches.

OK: The buzzer sounds.

HINT:

The buzzer circuit is built into the main body ECU, not into the buzzer itself.

NG: REPLACE MAIN BODY ECU

OK: END (WIRELESS DOOR LOCK BUZZER IS DEFECTIVE)

KEY REMINDER WARNING SYSTEM

PARTS LOCATION

NOTE:

When battery voltage is directly applied to the buzzer, the buzzer
does not sound.

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Door Lock - Tundra