Toyota 4Runner: IG Signal Circuit

Toyota 4Runner Service Manual / Vehicle Interior / Lighting (int) / Lighting System / IG Signal Circuit

DESCRIPTION

This circuit detects the ignition switch ON or off condition, and sends it to the main body ECU.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (IGNITION SWITCH)

(a) Using the Techstream, read the Data List (See page ).

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	-

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

OK:

Normal conditions listed above are displayed.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	CHECK HARNESS AND CONNECTOR (BATTERY - MAIN BODY ECU)

(a) Remove the main body ECU (See page ).

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A-32 (IG) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Main Body ECU)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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