Toyota Tacoma manuals

Toyota Tacoma (2015-2018) Service Manual: IG Signal Circuit

DESCRIPTION

This circuit detects whether the ignition switch is ON or off, and sends this information to the main body ECU (multiplex network body ECU).

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.

READ VALUE USING TECHSTREAM (IG SW)

(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 / Data List.

(e) According to the display on the Techstream, read the Data List.

Main Body

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

IG SW

Ignition switch ON signal / ON or OFF

ON: Ignition switch ON

OFF: Ignition switch off

"OFF" is also displayed for this item when the ignition switch is ACC.

OK:

The display is as specified in the normal condition column.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

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

(a) Disconnect the driver side junction block connectors.

(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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1D-5 - Body ground

Always

Below 1 Ω

Text in Illustration

*a

Front view of wire harness connector

(to Driver Side Junction Block)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

CHECK HARNESS AND CONNECTOR (IG POWER SOURCE CIRCUIT)

(a) Disconnect the driver side junction block connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

1A-16 - Body ground

Ignition switch ON

11 to 14 V

Text in Illustration

*a

Front view of wire harness connector

(to Driver Side Junction Block)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK DRIVER SIDE JUNCTION BLOCK

(a) Remove the driver side junction block (See page ).

(b) Reconnect the 1K, 1A and 1D driver side junction block connectors.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

MB-32 (IG) - Body ground

Ignition switch ON

11 to 14 V

Text in Illustration

*a

Component without harness connected

(Driver Side Junction Block)

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK

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