Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: High Beam Headlight Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the high beam headlights.

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 (HEAD LIGHT Hi)

(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

Head Light Hi

High beam headlights

ON/OFF

-

OK:

High beam headlights illuminate.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

INSPECT DIMMER RELAY

(a) Remove the headlight dimmer relay from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

Voltage is not applied between terminals 1 and 2

10 kΩ or higher

3 - 5

Voltage is applied between terminals 1 and 2

Below 1 Ω

NG

REPLACE DIMMER RELAY

OK

3.

CHECK HARNESS AND CONNECTOR (BATTERY - DIMMER RELAY)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Relay terminal 2 - Body ground

Always

11 to 14 V

Relay terminal 5 - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK HARNESS AND CONNECTOR (DIMMER RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Disconnect the M6 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Relay terminal 1 - M6-1 (DIM)

Always

Below 1 Ω

M6-1 (DIM) - Body ground

Always

10 kΩ or higher

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Door Unlock Detection Switch Circuit
DESCRIPTION The main body ECU (multiplex network body ECU) detects the condition of each door unlock detection switch. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: If the main body ECU (mul ...

Low Beam Headlight Circuit
DESCRIPTION The main body ECU (multiplex network body ECU) controls the low beam headlights. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to thi ...

Other materials:

Air Mix Damper Position Sensor Circuit (Passenger Side) (B1431/31)
DESCRIPTION This sensor detects the position of the air mix damper (for front passenger side) and sends the appropriate signals to the air conditioning amplifier assembly. The position sensor is built into the No. 2 air conditioning radiator damper servo sub-assembly (for front passenger side ...

Daytime Running Light Relay
Inspection INSPECTION PROCEDURE 1. INSPECT NO. 1 DAY TIME RUNNING LIGHT RELAY (a) Check the resistance. (1) Measure the resistance according to the value(s) in the table below. Standard: Tester Connection Condition Specified ...

Downhill Assist Control Switch Malfunction (Test Mode DTC) (C1379)
DESCRIPTION DTC C1379 is cleared when the crawl control switch sends a crawl control operation signal or when test mode ends. DTC Code DTC Detection Condition Trouble Area C1379 Stored only during test mode. Crawl ...

© 2011-2026 Copyright www.ttguide.net