Toyota Tacoma (2015-2018) Service Manual: Horn System

Toyota Tacoma (2015-2018) Service Manual / Horn / Horn System

Parts Location

PARTS LOCATION

ILLUSTRATION

Precaution

PRECAUTION

1. IGNITION SWITCH EXPRESSIONS

(a) The type of ignition switch used on this model differs depending on the specifications of the vehicle. The expressions listed in the table below are used in this section.

Expression	Ignition Switch (Position)	Engine Switch (Condition)
Ignition Switch off	LOCK	Off (Lock)
Ignition Switch ACC	ACC	On (ACC)
Ignition Switch ON	ON	On (IG)
Engine Start	START	Start

System Diagram

SYSTEM DIAGRAM

Data List / Active Test

DATA LIST / ACTIVE TEST

1. PERFORM ACTIVE TEST

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to 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
Vehicle Horn	Vehicle horns	ON/OFF	-

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

HORN SYSTEM

Symptom	Suspected Area	See page
Horn does not sound	HORN fuse	-
	HORN relay
	Horn button assembly	-
	Steering pad switch assembly
	Spiral cable with sensor sub-assembly
	Driver side junction block	-
	Harness or connector	-
Horn blows all the time	HORN relay
	Horn button assembly	-
	Steering pad switch assembly
	Spiral cable with sensor sub-assembly
	Driver side junction block	-
	Main body ECU (Multiplex network body ECU)	-
	Harness or connector	-

Horn Relay

On-vehicle Inspection ON-VEHICLE INSPECTION PROCEDURE 1. INSPECT HORN RELAY ASSEMBLY (a) Check the resistance. (1) Measure the resistance according to the value(s) in the table below ...

Low Pitched Horn

Components COMPONENTS ILLUSTRATION Inspection INSPECTION PROCEDURE 1. INSPECT LOW PITCHED HORN ASSEMBLY (a) Check the operation. (1) Apply battery voltage to the terminal 1 an ...

Other materials:

Theft Deterrent System Communication Line High Fixation (B279A,B279A12)
DESCRIPTION If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck high (e.g. shorted to +B), the ECM stores this DTC. DTC No. DTC Detection Condition Trouble Area DTC Output Confirmation Operation B279A*1 ...

Heater Relay
Inspection INSPECTION PROCEDURE 1. INSPECT HEATER RELAY (a) Check the resistance. (1) Using an ohmmeter, measure the resistance between each terminal. Standard: Tester Connection Specified Condition 3 - 4 ...

Terminals Of Ecu
TERMINALS OF ECU 1. CHECK POWER WINDOW REGULATOR MASTER SWITCH ASSEMBLY (a) for Double Cab (1) Disconnect the P18 power window regulator master switch assembly connector. (2) Measure the voltage and resistance according to the value(s) in the table below. HINT: Measure the values on the wi ...