AIRBAG SYSTEM Diagnosis Circuit

DESCRIPTION

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

DTCs are output by the blinking of the SRS warning light.

Tech Tips


  • When each warning light continues 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 the CAN communication system to each ECU, including the airbag ECU assembly. Thus, when all systems do not enter DTC output mode, there may be a hybrid vehicle control ECU malfunction.

WIRING DIAGRAM

B002IO1E05
*a Hybrid Vehicle Control ECU
*b Airbag ECU Assembly
*c CAN Communication Line

CAUTION / NOTICE / HINT

Note


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

    Click here

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

    Click here

  • After replacing the airbag ECU assembly, refer to initialization.

    Click here

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if a CAN communication DTC is output.

      Click here

      Result
      Proceed to
      DTCs are output
      DTC is not output

    DTCs are output

    GO TO CAN COMMUNICATION SYSTEM Click here

    DTC is not output

  2. CHECK HARNESS AND CONNECTOR (DLC3 - HYBRID VEHICLE CONTROL ECU)


    1. Turn the power switch off.

      B002J8VC01
      *a Front view of DLC3 *b

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

    2. Disconnect the connector from the Hybrid Vehicle Control ECU.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I7-13 (TC) - I116-28 (TC) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. B002K9JC20
      *a Front view of DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I7-4 (CG) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BODY GROUND)


    1. B002JUUC46
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I116-28 (TC) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU