Toyota Tundra Service Manual: 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 in the LOCK or ACC position. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends a key switch signal and front door courtesy light switch LH signal to the combination meter assembly.

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.

CHECK SEAT BELT WARNING BUZZER FUNCTION

(a) Check the seat belt warning buzzer function.

Click here

OK:

The seat belt warning buzzer sounds properly.

NG

GO TO SEAT BELT WARNING SYSTEM

OK

2.

CHECK FRONT DOOR COURTESY LIGHT SWITCH LH

(a) Open the driver door and check that the open door indicator on the combination meter assembly comes on.

OK:

Open door indicator comes on.

NG

GO TO DOOR COURTESY SWITCH CIRCUIT

OK

3.

CHECK UNLOCK WARNING SWITCH

(a) Check that the security indicator on the combination meter assembly turns off, when the key is inserted into the ignition key cylinder.

OK:

Security indicator light turns off.

HINT:

When the security indicator turns off, the transponder key ECU assembly has detected the unlock warning switch signal.

NG

GO TO UNLOCK WARNING SWITCH CIRCUIT

OK

4.

READ VALUE USING TECHSTREAM (Key Unlock Warning SW)

(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 / Main Body / Data List/

(e) According to the display on the Techstream, read on the Data List.

Main Body

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Key Unlock Warning SW

Unlock warning switch signal/ON or OFF

ON: Key is in ignition key cylinder

OFF: No key is in ignition cylinder

-

OK:

On the Techstream screen, ON or OFF is displayed for each item according to the table above.

HINT:

The unlock warning switch is confirmed to be functioning normally, and therefore if the result is NG, the problem is in the harness between the unlock warning switch and the main body ECU (multiplex network body ECU).

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

5.

CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - DRIVER SIDE JUNCTION BLOCK ASSEMBLY AND BODY GROUND)

(a) Disconnect the J18 unlock warning switch connector.

(b) Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

J18-1 - A-3 (KSW)

Always

Below 1 Ω

J18-2 - Body ground

Always

Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

6.

INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY

(a) Remove the driver side junction block assembly.

Click here

(b) Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly.

Click here

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3J-41 - A-3 (KSW)

Always

Below 1 Ω

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

NG

REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    How To Proceed With Troubleshooting

    Operation Check

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