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 sensor assembly. Thus, when all systems do not enter DTC output mode, there may be an ECM malfunction.

WIRING DIAGRAM

A004Q97E38
*a Airbag Sensor Assembly
*b CAN Communication Line

CAUTION / NOTICE / HINT

Note


  • After turning the ignition 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. Check if a CAN communication system DTC is output ( Click here).

      Result
      Result Proceed to
      DTCs are output A
      DTC is not output B

    A

    GO TO CAN COMMUNICATION Click here

    B

  2. CHECK HARNESS AND CONNECTOR (DLC3 - ECM)


    1. Turn the ignition switch off.

      A004P8OE02

    2. Disconnect the A83 connector from the ECM.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D8-13 (TC) - A83-50 (TC) Always Below 1 Ω
      Text in Illustration
      *a Front view of DLC3
      *b

      Front view of wire harness connector

      (to ECM)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A004N1IE02
      Text in Illustration
      *a Front view of DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D8-4 (CG) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A004R4JE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-50 (TC) - Body ground Always 1 MΩ or higher

    OK

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU