AIRBAG SYSTEM Diagnosis Circuit

DESCRIPTION

DTC output mode is set by connecting terminals TC and CG of the DLC3.

DTCs are displayed by blinking of the SRS warning light.

Tech Tips


  • 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.

  • A DTC output mode signal is transmitted through CAN communication system to each ECU including the center airbag sensor assembly. Thus when all systems do not enter DTC output mode, there may be an ECM malfunction.

WIRING DIAGRAM

A001AIBE04
*a CAN Line
*b Center Airbag Sensor Assembly
*c CAN Line

CAUTION / NOTICE / HINT

Note


  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

  • When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. for LHD:


      1. Check if a CAN communication system DTC is output Click here.

    2. for RHD:


      1. Check if a CAN communication system DTC is output Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK HARNESS AND CONNECTOR (DLC3 - ECM)

    A0018YUE01
    Front view of DLC3
    *1 Rear view of wire harness connector: (to ECM)

    1. Turn the engine switch off.

    2. Disconnect the A13 connector from ECM.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L31-13 (TC) - A13-21 (TC) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (CG OF DLC3 - BODY GROUND)

    A001EY4E01
    *1 Front view of DLC3:

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L31-4 (CG) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (TC OF ECM - BODY GROUND)

    A0018X8E03
    *1 Rear view of wire harness connector: (to ECM)

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A13-21 (TC) - Body ground Always 1 MΩ or higher

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU