Toyota Tacoma (2015-2018) Service Manual: 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.
(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 |
|---|---|---|---|
|
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 |
- |
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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:
Short to GND in Immobiliser System Power Source Circuit (B278A)
DESCRIPTION
When there is a short to GND in the power supply for the transponder key amplifier
of the engine switch, the certification ECU (smart key ECU assembly) stores this
DTC.
DTC Code
DTC Detection Condition
Trouble Area
DTC Output Confirmation ...
Accelerator Pedal
Components
COMPONENTS
ILLUSTRATION
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. INSPECT ACCELERATOR PEDAL SENSOR ASSEMBLY
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / En ...
Slip Indicator Light does not Come ON
DESCRIPTION
Refer to Slip Indicator Light Remains ON (See page
).
WIRING DIAGRAM
Refer to Slip Indicator Light Remains ON (See page
).
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (master cylinder solenoid), perform
calibration (See page
).
Inspe ...
