LIGHTING SYSTEM IG Signal Circuit

DESCRIPTION

• The main body ECU receives IG signal to control the following systems:




• Automatic light control system

• Light auto turn-off system

• Illuminated entry system

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch on (IG).

   3. Turn the intelligent tester on.

   4. Select the following menu items: Body Electrical / Main Body / Data List.

   5. Read the display on the intelligent tester.

      Main Body:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      IG SW	Ignition switch or engine switch IG signal / ON or OFF	ON: Ignition switch on (IG) OFF: Ignition switch off	-

      OK
      Normal conditions listed above are displayed.

   
   

   NG

   INSPECT FUSE (ECU-IG NO. 1) Click here

   OK

   PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

2. INSPECT FUSE (ECU-IG NO. 1)

   
   

   1. Remove the ECU-IG No. 1 fuse from the instrument panel junction block.

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

      Standard resistance
      Tester Connection Condition Specified Condition ECU-IG No. 1 fuse Always Below 1 Ω

   
   

   NG

   REPLACE FUSE

   OK

3. CHECK HARNESS AND CONNECTOR (IG POWER SOURCE CIRCUIT)

   
   

   1. 

      Measure the voltage between the loading slot of the fuse and body ground.

      Standard voltage
      Tester Connection Switch Condition Specified Condition ECU-IG No. 1 fuse terminal - Body ground Ignition switch off Below 1 V Ignition switch on (IG) 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)