Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: Some Alarm Functions do not Operate

Toyota Tacoma (2015-2018) Service Manual / Theft Deterrent / Theft Deterrent System / Some Alarm Functions do not Operate

DESCRIPTION

When the alarm sounds, the following alarm functions operate: the roof console box assembly and No. 1 room light assembly illuminates, and the headlights, taillights and hazard lights flash, and the security horn and vehicle horn sound intermittently.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration (See page ).*1
    • *1: w/ Smart Key System
  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK THEFT DETERRENT SYSTEM OPERATION

(a) Open the driver side window.

(b) Set the theft deterrent system.

(1) Close all doors and the hood.

(2) Lock the doors using wireless operation*1, key linked operation or entry operation*2.

  • *1: w/ Wireless Door Lock System
  • *2: w/ Smart Key System

(3) Wait for 30 seconds or more.

(c) After 30 seconds have elapsed, check that the security indicator light changes from illuminated to flashing.

(d) Unlock the driver door using the door lock knob.

(e) Check that each alarm component operates correctly.

Result

Result

Proceed to

Security horn is not activated

A

Vehicle horn is not activated

B

Headlights, taillights or hazard lights are not activated

C

Interior lights are not activated

D
B

GO TO STEP 9

C

GO TO LIGHTING SYSTEM

D

GO TO LIGHTING SYSTEM

A

2.

PERFORM ACTIVE TEST USING TECHSTREAM (SECURITY HORN)

(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 / Active Test.

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

Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Security Horn

Security horn assembly

OFF/ON

-

OK:

The security horn assembly sounds and stops correctly when operated through the Techstream.

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

3.

INSPECT S-HORN RELAY

(a) Remove the S-HORN relay from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

When battery voltage is not applied between terminals 1 and 2

10 kΩ or higher

3 - 5

When battery voltage is applied between terminals 1 and 2

Below 1 Ω
Text in Illustration

*1

S-HORN Relay
NG

REPLACE S-HORN RELAY
OK

4.

CHECK HARNESS AND CONNECTOR (BATTERY - S-HORN RELAY)

(a) Remove the S-HORN relay from the engine room relay block assembly.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1 (S-HORN relay holder) - Body ground

Always

11 to 14 V

5 (S-HORN relay holder) - Body ground

Always

11 to 14 V
Text in Illustration

*1

Engine Room Relay Block
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

INSPECT SECURITY HORN ASSEMBLY

(a) Remove the security horn assembly (See page (b) Inspect the security horn assembly (See page ).

(b) Inspect the security horn assembly (See page ).

NG

REPLACE SECURITY HORN ASSEMBLY

OK

6.

CHECK HARNESS AND CONNECTOR (S-HORN RELAY - SECURITY HORN ASSEMBLY)

(a) Remove the S-HORN relay from the engine room relay block assembly.

(b) Disconnect the S44 security horn assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 (S-HORN relay holder) - S44-1

Always

Below 1 Ω

3 (S-HORN relay holder) or S44-1 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

CHECK HARNESS AND CONNECTOR (S-HORN RELAY - DRIVER SIDE JUNCTION BLOCK)

(a) Remove the S-HORN relay from the engine room relay block assembly.

(b) Disconnect the 1F driver side junction block connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2 (S-HORN relay holder) - 1F-31

Always

Below 1 Ω

2 (S-HORN relay holder) or 1F-31 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

INSPECT DRIVER SIDE JUNCTION BLOCK

(a) Remove the main body ECU (multiplex network body ECU) (See page (b) Disconnect the driver side junction block connector. ).

(b) Disconnect the driver side junction block connector.

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

Text in Illustration

*a

Component without harness connected

(Driver Side Junction Block )

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

1F-31 - MB-29 (SH)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK

9.

CHECK HORN OPERATION

(a) Press the horn switch and check if the horn sounds.

OK:

Horn sounds

NG

GO TO HORN SYSTEM

OK

10.

INSPECT DRIVER SIDE JUNCTION BLOCK

(a) Remove the main body ECU (multiplex network body ECU) (See page (b) Disconnect the driver side junction block connector. ).

(b) Disconnect the driver side junction block connector.

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

Text in Illustration

*a

Component without harness connected

(Driver Side Junction Block)

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

1F-26 - MB-28 (HORN)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK

Theft Deterrent System Unexpectedly Sets Itself
DESCRIPTION A situation in which the theft deterrent system unexpectedly sets itself can be caused when the main body ECU (multiplex network body ECU) cannot detect whether a door is open or clos ...

While Alarm is Armed, Battery is Reconnected but Alarm does not Sound
DESCRIPTION While the alarm is armed, the EEPROM inside the main body ECU (multiplex network body ECU) will remember the armed state even if the battery is disconnected, and the alarm will sound ...

Other materials:

Terminals Of Ecu
TERMINALS OF ECU 1. OCCUPANT DETECTION ECU Symbols (Terminal No.) Wiring Color Terminal Description Condition Specification +B (O5-1) - GND (O5-3) R - W-B Battery Ignition switch on ...

Short in Front Passenger Side Knee Airbag Squib Circuit (B1865/65-B1868/65)
DESCRIPTION The passenger side knee airbag squib circuit consists of the airbag sensor assembly and lower No. 2 instrument panel airbag assembly. The airbag sensor assembly uses this circuit to deploy the airbag when deployment conditions are met. These DTCs are stored when a malfunction is de ...

If your vehicle needs to be towed
If towing is necessary, we recommend having your vehicle towed by your Toyota dealer or a commercial towing service, using a lift-type truck or a flat bed truck. Use a safety chain system for all towing, and abide by all state/provincial and local laws. The wheels and axle on the ground must b ...

© 2011-2026 Copyright www.ttguide.net