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:

Hydraulic Test
HYDRAULIC TEST 1. PERFORM HYDRAULIC TEST (a) Measure the line pressure. CAUTION: The line pressure test should always be performed with at least 2 people. One person should observe the condition of the wheels and wheel chocks while the other is performing the test. NOTICE: Perform ...

Drive Belt
Components COMPONENTS ILLUSTRATION Precaution PRECAUTION NOTICE: Do not apply or add oil or grease to the belt tensioner to prevent abnormal noises from the belt tensioner pulley, belt squealing, etc. Do not allow oil or grease to adhere to the moving parts of the belt ...

Inspection
INSPECTION PROCEDURE 1. INSPECT INPUT SHAFT (a) Using a dial indicator and 2 V-blocks, measure the shaft runout. Maximum runout: 0.03 mm (0.0012 in.) If the runout is more than the maximum, replace the input shaft. HINT: Measure the 3 areas shown in the illustration wit ...