Toyota Corolla Cross: Key Reminder Buzzer does not Sound

DESCRIPTION

The key reminder warning buzzer sounds when the driver door is opened while the ignition switch is off or ACC. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends an un-lock warning switch signal and driver door courtesy light switch signal to the combination meter assembly via CAN communication.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The key reminder warning system uses the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the key reminder warning system after confirming that the communication systems are functioning properly.

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PROCEDURE

1.	PERFORM ACTIVE TEST USING GTS (BUZZER OPERATION)

(a) Perform the Active Test according to the display on the GTS.

Body Electrical > Combination Meter > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Buzzer Operation (800Hz, Vol L, W/ Damping)	Combination meter buzzer Frequency: 800Hz Volume: Large Fading tone	ON	-

Body Electrical > Combination Meter > Active Test

Tester Display
Buzzer Operation (800Hz, Vol L, W/ Damping)

Result	Proceed to
Combination meter buzzer sounds	A
Combination meter buzzer does not sound	B

B

REPLACE COMBINATION METER ASSEMBLY

A

2.	READ VALUE USING GTS (FL DOOR COURTESY SW STATUS)

(a) Read the Data List according to the display on the GTS.

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FL Door Courtesy Switch Status	Front door courtesy light switch assembly LH signal	Close or Open	Close: Front door LH closed Open: Front door LH open	-

Body Electrical > Main Body > Data List

Tester Display
FL Door Courtesy Switch Status

OK:

The GTS indicates ON or OFF according to the driver door conditions shown in the table.

NG

GO TO LIGHTING SYSTEM

OK

3.	READ VALUE USING GTS (KEY UNLOCK WARNING SW)

(a) Read the Data List according to the display on the GTS.

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Key Unlock Warning Switch	Un-lock warning switch signal	OFF or ON	OFF: Ignition key not inserted ON: Ignition key inserted	-

Body Electrical > Main Body > Data List

Tester Display
Key Unlock Warning Switch

OK:

The GTS indicates ON or OFF according to whether the key is in the ignition key cylinder.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

4.	INSPECT UN-LOCK WARNING SWITCH ASSEMBLY

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NG

REPLACE UN-LOCK WARNING SWITCH ASSEMBLY

OK

5.	CHECK HARNESS AND CONNECTOR (UN-LOCK WARNING SWITCH ASSEMBLY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND BODY GROUND)

(a) Disconnect the I85 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I85-16 (KSW) - I13-1 (UN+)	Always	Below 1 Ω
I13-2 (UN-) - Body ground	Always	Below 1 Ω
I85-16 (KSW) or I13-1 (UN+) - Other terminals and body ground	Always	10 kΩ or higher

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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