Toyota Tacoma (2015-2018) Service Manual: Key Reminder Buzzer does not Sound

Toyota Tacoma (2015-2018) Service Manual / 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 in the LOCK or ACC positions. The key reminder warning buzzer is activated when the main body ECU (multiplex network body ECU) sends a key switch signal and driver side courtesy light switch 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 the CAN communication functions in accordance with How to Proceed with Troubleshooting. Then conduct the following troubleshooting procedure.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (FL DOOR COURTESY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON (IG).

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

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

Main Body

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

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

FL Door Courtesy

Front LH door courtesy light switch signal / ON or OFF

ON: Front LH door closed

OFF: Front LH door opened

OK:

When the front door courtesy light switch assembly LH is operated, the display changes as shown in the table.

GO TO LIGHTING SYSTEM (DOOR COURTESY LIGHT SWITCH CIRCUIT)

2.	READ VALUE USING TECHSTREAM (KEY UNLOCK WARNING SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON (IG).

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

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

Main Body

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Key Unlock Warning SW	Unlock warning switch / OFF or ON	OFF: Ignition key is not inserted ON: Ignition key is inserted	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Key Unlock Warning SW

Unlock warning switch / OFF or ON

OFF: Ignition key is not inserted

ON: Ignition key is inserted

OK:

When the unlock warning switch is operated, the display changes as shown in the table.

GO TO STEP 4

3.	CHECK COMBINATION METER ASSEMBLY (BUZZER OPERATION)

(a) Remove the key from the key cylinder, turn the light control switch on the headlight dimmer switch assembly to the tail position, and open the driver door.

OK:

The light reminder warning buzzer sounds.

HINT:

The key reminder warning system sounds the buzzer built in to the combination meter for key reminder warnings. This buzzer is also used for the light reminder warning system. Therefore, check the operation of the combination meter buzzer by checking if the buzzer sounds to inform that the lights are still on.

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE COMBINATION METER ASSEMBLY

4.	INSPECT UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch assembly (See page (b) Inspect the unlock warning switch assembly. ).

(b) Inspect the unlock warning switch assembly.

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

Text in Illustration

Component without harness connected

(Unlock Warning Switch Assembly)

Switch not pushed

Switch pushed

Standard Resistance

Tester Connection	Condition	Specified Condition
1 - 2	Switch not pushed (Key removed)	10 kΩ or higher
1 - 2	Switch pushed (Key inserted)	Below 1 Ω

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

5.	CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK - UNLOCK WARNING SWITCH ASSEMBLY)

(a) Disconnect the U1 unlock warning switch and 1D driver side junction block connectors.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
U1-1 - 1D-31	Always	Below 1 Ω
U1-2 - Body ground	Always	Below 1 Ω
U1-1 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	INSPECT DRIVER SIDE JUNCTION BLOCK

(a) Remove the main body ECU (multiplex network body ECU) (See page (b) Measure the resistance according to the value(s) in the table below. ).

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

Component without harness connected

(Driver Side Junction Block)

Standard Resistance:

Tester Connection	Condition	Specified Condition
MB-3 (KSW) - 1D-31	Always	Below 1 Ω
MB-3 (KSW) or 1D-31 - Body ground	Always	10 Ω or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE DRIVER SIDE JUNCTION BLOCK

Terminals Of Ecu

TERMINALS OF ECU 1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND DRIVER SIDE JUNCTION BLOCK (a) Remove the main body ECU (multiplex network body ECU) from the driver side junction bloc ...

Power Door Lock Control System

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