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

Toyota Tacoma (2015-2018) Service Manual / Lighting / Lighting System / 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

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.

(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.

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.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

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

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)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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.

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)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE DRIVER SIDE JUNCTION BLOCK

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 ...

Turn Signal Switch Circuit

DESCRIPTION The combination meter assembly receives the turn signal switch information and controls the turn signal lights. WIRING DIAGRAM PROCEDURE 1. READ VALUE USING ...

Other materials:

Components
COMPONENTS ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ILLUSTRATION ...

Precaution
PRECAUTION 1. IGNITION SWITCH EXPRESSIONS (a) The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section. Expression Ignition Switch (Position) Engine ...

Transmitter ID not Registered (C2171/71)
DESCRIPTION The IDs of each tire pressure warning valve and transmitter are registered to the tire pressure warning ECU and receiver. When the ECU detects that a transmitter ID code is not registered in the ECU, this DTC is stored. DTC No. Detection Item DTC D ...