Toyota Camry (XV70): 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 unlock 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 TECHSTREAM (Buzzer Operation)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

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 TECHSTREAM (FL Door Courtesy SW)

(a) Enter the following menus: Body Electrical / Main Body / Data List.

(b) Read the Data List according to the display on the Techstream.

Body Electrical > Main Body > Data List

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

Body Electrical > Main Body > Data List

Tester Display
FL Door Courtesy SW

OK:

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

NG

GO TO STEP 7

OK

3.	READ VALUE USING TECHSTREAM (Key Unlock Warning SW)

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

Body Electrical > Main Body > Data List

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

Body Electrical > Main Body > Data List

Tester Display
Key Unlock Warning SW

OK:

The Techstream 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 UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch assembly.

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(b) Inspect the unlock warning switch assembly.

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NG

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

OK

5.	CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3A instrument panel junction block assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3A-41 - K31-1 (UN+)	Always	Below 1 ?
K31-2 (UN-) - Body ground	Always	Below 1 ?
K31-1 (UN+) or 3A-41 - Body ground	Always	10 k? or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

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*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3A-41 - MB-3 (KSW)	Always	Below 1 ?

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

7.	INSPECT FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for LH)

(a) Remove the front door courtesy light switch assembly (for LH).

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(b) Inspect the front door courtesy light switch assembly (for LH).

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NG

REPLACE FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for LH)

OK

8.	CHECK HARNESS AND CONNECTOR (FRONT DOOR COURTESY LIGHT SWITCH ASSEMBLY (for LH) - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the K52 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
R5-1 - K52-1 (FLCY)	Always	Below 1 ?
R5-1 or K52-1 (FLCY) - Body ground	Always	10 k? or higher

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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