PRE-CRASH SAFETY SYSTEM > Power Source Circuit

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DESCRIPTION

This circuit supplies power to the seat belt control ECU.

WIRING DIAGRAM


B274780E01


INSPECTION PROCEDURE

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

1.CHECK HARNESS AND CONNECTOR (GND CIRCUIT)


    E172287E26

  1. Disconnect the seat belt control ECU connector.

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

    Standard Resistance:
    Tester Display
    		Condition
    		Specified Condition
    H6-8 (PGND) - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Seat Belt Control ECU)

  1. Reconnect the seat belt control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK


2.CHECK HARNESS AND CONNECTOR (IG1 CIRCUIT)


    E172286E13

  1. Disconnect the seat belt control ECU connector.

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Display
    		Condition
    		Specified Condition
    H7-8 (IG1) - H6-8 (PGND)
    		Power switch on (IG)
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Seat Belt Control ECU)
    *b
    		Front view of wire harness connector
    (to Seat Belt Control ECU)

  1. Reconnect the seat belt control ECU connector.



NG
Go to step 4
OK


3.CHECK HARNESS AND CONNECTOR (+B CIRCUIT)


    E172287E27

  1. Disconnect the seat belt control ECU connector.

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

    Standard Voltage:
    Tester Display
    		Condition
    		Specified Condition
    H6-7 (+B) - Body ground
    		Power switch off
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Seat Belt Control ECU)

  1. Reconnect the seat belt control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (+B CIRCUIT)
OK

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

4.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


  1. Remove the instrument panel junction block assembly (Click here).


    B265904E01


    Text in Illustration 
    *a
    		Component without harness connected
    (Instrument Panel Junction Block Assembly)
    		-
    		-

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2E*1-1 - 2B-2
    		Always
    		10 kΩ or higher
    2F*2-1 - 2B-2
    2E*1-1 - 2B-2
    		When auxiliary battery voltage applied to terminals 2B-25 and 2B-6
    		Below 1 Ω
    2F*2-1 - 2B-2

    1. *1: for LHD
    2. *2: for RHD

  1. Reinstall the instrument panel junction block assembly.



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (Click here)
OK


5.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - SEAT BELT CONTROL ECU)

  1. Disconnect the instrument panel junction block assembly connector.

  1. Disconnect the seat belt control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2B-2 - H7-8 (IG1)
    		Always
    		Below 1 Ω
    2B-2 - Body ground
    		Always
    		10 kΩ or higher
    H7-8 (IG1) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the seat belt control ECU connector.

  1. Reconnect the instrument panel junction block assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - SEAT BELT CONTROL ECU)
OK


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

  1. Disconnect the instrument panel junction block assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2B-6 - Body ground
    		Always
    		Below 1 Ω

  1. Reconnect the instrument panel junction block assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)
OK


7.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER MANAGEMENT ECU)

  1. Disconnect the instrument panel junction block assembly connector.

  1. Disconnect the power management control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2B-25 - H4-2 (IG1D)
    		Always
    		Below 1 Ω
    2B-25 - Body ground
    		Always
    		10 kΩ or higher
    H4-2 (IG1D) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the power management control ECU connector.

  1. Reconnect the instrument panel junction block assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER MANAGEMENT ECU)
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - AUXILIARY BATTERY)