RX400h · Service Manual SECURITIES

ECU Power Source Circuit

Circuit diagnosis

DESCRIPTION

This circuit provides power for multiplex network body ECU operation.

WIRING DIAGRAM

B109004E02

INSPECTION PROCEDURE


1. INSPECT FUSE (ECU-B NO.1)

  1. Remove the ECU-B NO.1 fuse from the fusible link block.

  1. Measure the resistance.

    Resistance:
    Below 1 Ω



 NG
REPLACE FUSE
OK


2. CHECK INSTRUMENT PANEL J/B ASSEMBLY (MULTIPLEX NETWORK BODY ECU) (POWER SOURCE)

  1. Install the ECU-B NO.1 fuse to the fusible link block.

  1. B110545E01
    Disconnect the 1D J/B connector.

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

    Voltage:
    Symbol (Tester Connection)
    		 Specified Condition
    BECU (1D-10) - Body ground
    		 10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. B110543E01
    Disconnect the 1F and 1M J/B connectors.

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

    Resistance:
    Symbol (Tester Connection)
    		 Specified Condition
    GND1 (1F-10) - Body ground
    		 Below 1 Ω
    GND2 (1M-9) - Body ground



 NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE INSTRUMENT PANEL J/B ASSEMBLY


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