Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: Taillight Relay Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the operation of the TAIL relay.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (TAILLIGHT RELAY)

(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

Taillight Relay

Taillight relay

ON/OFF

-

OK:

Taillight relay operates. (Taillights illuminate.)

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

CHECK HARNESS AND CONNECTOR (BATTERY - DRIVER SIDE JUNCTION BLOCK)

(a) Disconnect the 1K driver side junction block connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1K-1 - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

INSPECT DRIVER SIDE JUNCTION BLOCK

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

(b) Remove the main body ECU (multiplex network body ECU) from the driver side junction block.

Text in Illustration

*a

Component without harness connected

(Driver Side Junction Block)

-

-

(c) Connect a positive (+) lead from the battery to terminal 1K-1.

(d) Connect a negative (-) lead from the battery to terminal MB-14 (TRLY).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

1F-3 - Battery negative terminal

Always

11 to 14 V

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK

Engine Switch Illumination Circuit
DESCRIPTION The illuminated entry system controls the engine switch illumination. WIRING DIAGRAM PROCEDURE 1. READ VALUE USING TECHSTREAM (POWER/ENGINE SW LIGHT) ...

Cargo Light Circuit
DESCRIPTION The main body ECU (multiplex network body ECU) receives a cargo light information signal from the deck light switch assembly and door courtesy light switch, and illuminates the cargo ...

Other materials:

Operation Check
OPERATION CHECK 1. CHECK FUNCTION (a) Check that the key reminder warning buzzer sounds. (1) With the driver side door closed, insert the key into the ignition key cylinder and then turn the key to LOCK or ACC. (2) Check that the buzzer sounds intermittently when the driver side door is open ...

Reassembly
REASSEMBLY PROCEDURE 1. INSTALL FRONT BUMPER COVER INSERT LH (a) Engage the clip to install the front bumper cover insert LH. (b) Install the bolt. Torque: 5.9 N·m {60 kgf·cm, 52 in·lbf} 2. INSTALL FRONT BUMPER COVER INSERT RH HINT: U ...

Automatic High Beam System does not Operate or Operation Indicator does not Illuminate
DESCRIPTION The main body ECU (multiplex network body ECU) controls the automatic high beam system based on signals received from the forward recognition camera. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: When replacing the combination meter assembly, always replace it with ...

© 2011-2025 Copyright www.ttguide.net