RX400h · Service Manual RESTRAINTS

Diagnosis Circuit

Circuit diagnosis

DESCRIPTION

DTC output mode is set by connecting terminals TC and CG of the DLC3.
DTCs are displayed by blinking the SRS warning light.

HINT:
  1. Make sure that DTC B1281 has not been output. If DTC B1281 has been output, refer to the multiplex communication system.
  2. When each warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
  3. A DTC output mode signal is transmitted through BEAN to each ECU including the center airbag sensor assembly, except for the skid control ECU with actuator. Thus when all systems except the ABS system do not enter DTC output mode, it can be suspected that there is an ECM malfunction.


WIRING DIAGRAM

C116300E01
C111749E02

INSPECTION PROCEDURE


1. CHECK WIRE HARNESS (DLC3 - ECM)

  1. C111739E01
    Turn the ignition switch to the LOCK position.

  1. Disconnect the center airbag sensor assembly connector.

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

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    D1-13 (TC) -
    H29-3 (TC)
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE WIRE HARNESS (TC OF DLC3 - TC OF HYBRID VEHICLE CONTROL ECU)
OK


2. CHECK WIRE HARNESS (CG OF DLC3 - BODY GROUND)

  1. H040173E19
    Measure the resistance according to the value(s) in the table below.

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    D1-4 (CG) -
    Body ground
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE WIRE HARNESS (CG OF DLC3 - BODY GROUND)
OK


3. CHECK WIRE HARNESS (TC OF HYBRID VEHICLE CONTROL ECU - BODY GROUND)

  1. E110177E04
    Measure the resistance according to the value(s) in the table below.

    Resistance:
    Tester connection
    		 Condition
    		 Specified condition
    H29-3 (TC) -
    Body ground
    		 Always
    		 1 MΩ or higher



NG
REPAIR OR REPLACE WIRE HARNESS OR EACH ECU
OK


4. REPLACE ECM

  1. Check that the ECM.

    Result:
    A:
    Normal system code is output.
    B:
    DTC is output.
    C:
    ECM does not set the DTC output mode.



 A
END

B
GO TO INSPECTION PROCEDURE OF DTC OUTPUT
C

REPLACE CENTER AIRBAG SENSOR ASSEMBLY


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