Toyota Sienna Service Manual: No Answer-Back (Hazard Warning Light and Wireless Door Lock Buzzer)

DESCRIPTION If there is no answer-back of the hazard light signal and the wireless door lock buzzer although the wireless control function is operating normally, there might be a malfunction in the hazard light signal and the wireless door lock buzzer signal which are output from the multiplex network body ECU.

NOTICE: Troubleshooting should be started after confirming that the answer-back function has been switched ON through customization.

WIRING DIAGRAM

INSPECTION PROCEDURE

When using intelligent tester:

1 CHECK WIRELESS DOOR LOCK CONTROL SYSTEM

1. Check whether the wireless door lock functions by operating the transmitter switch.

HINT: When the wireless door LOCK/UNLOCK operation can be performed, it means that the wireless signal from the transmitter is properly input to the multiplex network body ECU

Result

2 PERFORM ACTIVE TEST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.
2.  Turn the ignition switch ON and push the intelligent tester main switch ON.
3.  Select the item "HAZARD" in the ACTIVE TEST and check the turn signal flasher relay ON/OFF.
4.  Select the item "BUZZ RESP SOUND" in the ACTIVE TEST and check the wireless buzzer ON/OFF

BODY:

Result

3 CHECK HAZARD WARNING LIGHTS

1. Check that the hazard warning lights blink when the hazard warning signal switch is pressed.

REPLACE MULTIPLEX NETWORK BODY ECU

4 INSPECT WIRELESS DOOR LOCK BUZZER

1. Check the buzzer resistance.

NOTICE:

•  The buzzer circuit is built into the ECU, not into the buzzer itself.
•  When battery voltage is directly applied to the buzzer, the buzzer does not sound.

1.  Check the resistance between terminals of the buzzer.

Standard

5 CHECK HARNESS AND CONNECTOR (WIRELESS DOOR LOCK BUZZER - MULTIPLEX NETWORK BODY ECU)

1. Disconnect the K1 buzzer connector and B8 ECU connector.
2.  Measure the resistance according to the value(s) in the table below.

Standard resistance

REPLACE MULTIPLEX NETWORK BODY ECU

When not using intelligent tester:

1 CHECK WIRELESS DOOR LOCK CONTROL SYSTEM

1. Check whether the wireless door lock functions by operating the transmitter switch.

HINT: When the wireless door LOCK/UNLOCK operation can be performed, it means that the wireless signal from the transmitter is properly input to the multiplex network body ECU

Result

2 CHECK HAZARD WARNING LIGHTS

1. Check that the hazard warning lights blink when the hazard warning signal switch is pressed.

REPLACE MULTIPLEX NETWORK BODY ECU

3 INSPECT WIRELESS DOOR LOCK BUZZER

1. Check the buzzer resistance.

NOTICE:

•  The buzzer circuit is built into the body ECU, not into the buzzer itself.
•  When battery voltage is directly applied to the buzzer, the buzzer does not sound.

1.  Check the resistance between terminals of the buzzer.

Standard resistance

4 CHECK HARNESS AND CONNECTOR (WIRELESS DOOR LOCK BUZZER - MULTIPLEX NETWORK BODY ECU)

1. Disconnect the K1 wireless buzzer connector and B8 ECU connector.
2.  Measure the resistance according to the value(s) in the table below.

Standard resistance

REPLACE MULTIPLEX NETWORK BODY ECU