PRE-CRASH SAFETY SYSTEM Power Source Circuit

DESCRIPTION

This circuit supplies power to the seat belt control ECU.

WIRING DIAGRAM

A004WCRE02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (GND CIRCUIT)


    1. A004Z4EE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the seat belt control ECU connector.

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

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

    3. Reconnect the seat belt control ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  2. CHECK HARNESS AND CONNECTOR (IG1 CIRCUIT)


    1. A004W1XE01
      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)

      Disconnect the seat belt control ECU connector.

    2. Turn the power switch on (IG).

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

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

    4. Reconnect the seat belt control ECU connector.


    NG

    INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (+B CIRCUIT)


    1. A004W53E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the seat belt control ECU connector.

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

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

    3. Reconnect the seat belt control ECU connector.


    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+B CIRCUIT)

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


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

      A004WWVE02
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 *1 LHD
      *2 RHD - -

    2. 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: for LHD

      • *2: for RHD

    3. 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.

    2. Disconnect the seat belt control ECU connector.

    3. 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

    4. Reconnect the seat belt control ECU connector.

    5. 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.

    2. 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

    3. 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.

    2. Disconnect the power management control ECU connector.

    3. 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

    4. Reconnect the power management control ECU connector.

    5. Reconnect the instrument panel junction block assembly connector.


    OK

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

    NG

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