THEFT DETERRENT SYSTEM > Ignition Switch Circuit

for Preparation Click here


DESCRIPTION

The main body ECU determines the ignition switch position (OFF, ACC, ON) based on signals from the IG or ACC circuit.

WIRING DIAGRAM


B214145E01


INSPECTION PROCEDURE

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

1.READ VALUE USING INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Body Electrical / Main Body / Data List.

  1. According to the display on the intelligent tester, 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 is ON
    OFF: Ignition switch is off
    		-
    ACC SW
    		Ignition switch ACC signal/ON or OFF
    		ON: Ignition switch is ACC
    OFF: Ignition switch is off
    		-

    OK:
    When the ignition switch is operated, the display changes as shown in the table.



NG
Go to step 2
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)  

2.CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK)


    E178150E01

  1. Disconnect the 3A junction block connector.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    3A-1 - Body ground
    		Ignition switch ON
    		11 to 14 V

Text in Illustration 
*1
Front view of wire harness connector
(to Instrument Panel Junction Block)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT IGNITION SWITCH ASSEMBLY


    B216887E01

  1. Remove the ignition switch (Click here).

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    2 - 3
    		Ignition switch ON
    		Below 1 Ω
    2 - 4
    3 - 4
    2 - 3
    		Ignition switch ACC
    		Below 1 Ω

    Text in Illustration 
    *1
    		Component without harness connected
    (Ignition Switch)



NG
REPLACE IGNITION SWITCH ASSEMBLY (Click here)
OK


4.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - INSTRUMENT PANEL JUNCTION BLOCK)

  1. Reinstall the ignition switch.



    B214123E01

  1. Disconnect the 3C and 3D junction block connector.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    3C-23 - 3D-28
    		Ignition switch ON
    		Below 1 Ω
    3D-28 - 3D-27
    		Ignition switch ACC
    		Below 1 Ω

Text in Illustration 
*1
Front view of wire harness connector
(to Instrument Panel Junction Block)
*2
Front view of wire harness connector
(to Instrument Panel Junction Block)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BODY GROUND)


    B216888E01

  1. Disconnect the 3C junction block connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3C-10 - Body ground
    		Always
    		Below 1 Ω

Text in Illustration 
*1
Front view of wire harness connector
(to Instrument Panel Junction Block)


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.REPLACE MAIN BODY ECU

  1. Temporarily replace the main body ECU with a new or normally functioning one (Click here).


NEXT


7.READ VALUE USING INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Body Electrical / Main Body / Data List.

  1. According to the display on the intelligent tester, 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 is ON
    OFF: Ignition switch is off
    		-
    ACC SW
    		Ignition switch ACC signal/ON or OFF
    		ON: Ignition switch is ACC
    OFF: Ignition switch is off
    		-

    OK:
    When the ignition switch is operated, the display changes as shown in the table.



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK
OK

END (MAIN BODY ECU IS DEFECTIVE)