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:

Diagnosis System
DIAGNOSIS SYSTEM 1. DESCRIPTION The ECM stores DTCs (Diagnostic Trouble Codes) when trouble occurs on the vehicle. The diagnosis system allows reading of DTCs stored in the ECM when a the Techstream is connected to the DLC3 (Data Link Connector 3). If the CRUISE MAIN indicator light does not ...

Display does not Dim when Light Control Switch is Turned ON
PROCEDURE 1. CHECK IMAGE QUALITY SETTING (a) Display the "Display" screen. (b) Turn the light control switch to the tail or head position. (c) Check if "Day Mode" on the display adjustment screen is on. OK: "Day Mode" setting is of ...

Transmission Fluid Temperature Sensor "B" Circuit Short to Ground (P274011)
DESCRIPTION The No. 2 ATF temperature sensor is installed in the transmission valve body assembly. If the ECM detects an abnormally high ATF temperature near this sensor, it illuminates the warning indicator. HINT: The temperature of ATF easily rises when towing, climbing hills, in ...