Toyota 4Runner: Key Reminder Buzzer does not Sound

Toyota 4Runner Service Manual / Vehicle Interior / Door Lock / Key Reminder Warning System / Key Reminder Buzzer does not Sound

DESCRIPTION

The key reminder warning buzzer sounds when the driver side door is opened while the ignition switch is ACC or off and the key is in the ignition key cylinder. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends an unlock warning switch signal and front door courtesy light switch LH signal to the combination meter.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Since the key reminder warning system has functions that use CAN communication, first confirm that there is no malfunction in the communication system by inspecting CAN communication in accordance with the "How to Proceed with Troubleshooting" procedures. Then, conduct the following inspection procedure.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (FRONT DOOR COURTESY LIGHT SWITCH)

(a) Check the Data List for proper functioning of the front door courtesy light switch (See page ).

Main Body

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
FL Door Courtesy	Front door courtesy light switch LH signal / ON or OFF	ON: Front door LH closed OFF: Front door LH open	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

FL Door Courtesy

Front door courtesy light switch LH signal / ON or OFF

ON: Front door LH closed

OFF: Front door LH open

OK:

On tester screen, each item changes between ON and OFF according to above chart.

GO TO LIGHTING SYSTEM (INT)

2.	READ VALUE USING TECHSTREAM (UNLOCK WARNING SWITCH)

(a) Check the Data List for proper functioning of the unlock warning switch (See page ).

Main Body

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Key Unlock Warning SW	Unlock warning switch signal / ON or OFF	ON: Key in ignition key cylinder OFF: No key in ignition key cylinder	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Key Unlock Warning SW

Unlock warning switch signal / ON or OFF

ON: Key in ignition key cylinder

OFF: No key in ignition key cylinder

OK:

On tester screen, each item changes between ON and OFF according to above chart.

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

3.	INSPECT UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch (See page ).

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
1 (UN+) - 2 (UN-)	Not pushed	10 kΩ or higher
1 (UN+) - 2 (UN-)	Pushed	Below 1 Ω

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - MAIN BODY ECU AND BODY GROUND)

(a) Disconnect the F18 unlock warning switch connector.

(b) Disconnect the F9 main body ECU connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F18-1 (UN+) - F9-17 (KSW)	Always	Below 1 Ω
F18-2 (UN-) - Body ground	Always	Below 1 Ω
F9-17 (KSW) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK COMBINATION METER ASSEMBLY (OPERATION)

(a) Temporarily replace the combination meter assembly with a new or normally functioning one (See page ).

(b) Check the key reminder warning system (See page ).

OK:

The key reminder warning system functions properly.

END (COMBINATION METER ASSEMBLY IS DEFECTIVE)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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