Ignition Switch Circuit

DESCRIPTION

When the ignition switch is turned to the ON position, battery positive voltage is applied to terminal IG of the multiplex network body ECU.

WIRING DIAGRAM

INSPECTION PROCEDURE

1. READ DATA LIST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON.

3. Turn the intelligent tester main switch on.

4. Select the item below in the DATA LIST and read the display on the tester.

   BODY (Multiplex network body ECU): 

   Item	Test Details	Diagnostic Note
   IG SW	Ignition switch signal ON/OFF	-

   OK:

   When turning the ignition switch on and off, the intelligent tester display changes between "ON" and "OFF".
   

NG	Go to step 2

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2. INSPECT FUSES (ECU-IG NO.1, AM1)

1. Remove the ECU-IG NO.1 and AM1 fuses from the instrument panel J/B.

2. Measure the resistance.

   Resistance:

   Below 1 Ω
   

NG	REPLACE FUSES

OK

3. INSPECT RELAY (IG1)

1. Install the ECU-IG NO.1 and AM1 fuses to the instrument panel J/B.

2. Remove the IG1 relay from the instrument panel J/B.

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

   Resistance:

   Tester Condition	Specified Condition
   3 - 5	10 kΩ or higher
   	Below 1 Ω (When battery voltage is applied to terminals 1 and 2)

NG	REPLACE RELAY

OK

4. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY

1. Install the IG1 relay to the instrument panel J/B.

2. Disconnect the I14 switch connector.

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

   Resistance:

   Tester Connection	Switch Position	Specified Condition
   2 - 4	ON	Below 1 Ω

NG	REPLACE IGNITION OR STARTER SWITCH ASSEMBLY

OK

5. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL J/B ASSEMBLY)

1. Connect the I14 switch connector.

2. Disconnect the 1A J/B connector.

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

   Voltage:

   Symbol (Tester Connection	Switch Position	Specified Condition
   IG (1A-1) - Body ground	Ignition switch ON	10 to 14 V

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL J/B - INSTRUMENT PANEL J/B)

1. Disconnect the 1I J/B connector.

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

   Resistance:

   Tester Connection	Switch Position	Specified Condition
   1I-4 - 1I-9	Ignition switch ON	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL J/B (BODY ECU) - BODY GROUND)

1. Disconnect the 1F J/B connector.

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

   Resistance:

   Tester Connection	Specified Condition
   1F-10 - Body ground	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE INSTRUMENT PANEL J/B ASSEMBLY