CAN COMMUNICATION SYSTEM Center Airbag Sensor Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Center Airbag Sensor Communication Stop Mode

Any of the following conditions are met:


  • Communication stop for "Airbag" is indicated on the "Communication Bus Check" screen of the GTS.

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  • Communication system DTCs (DTCs that start with U) that correspond to "Center Airbag Sensor Communication Stop Mode" in "DTC Combination Table" are output.

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  • Airbag ECU assembly branch wire or connector

  • Power source circuit of airbag ECU assembly

  • Airbag ECU assembly ground circuit

  • Airbag ECU assembly

WIRING DIAGRAM

B002JOJE43
*1 No. 2 CAN Junction Connector
*2 A/BAG
*3 from IG2-MAIN Relay
*4 Airbag ECU Assembly

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

Note


  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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  • Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • 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.

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  • Some parts must be initialized and set when replacing or removing and installing parts.

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  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

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  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (AIRBAG ECU ASSEMBLY BRANCH WIRE)


    1. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

    2. B002IWEC28
      *a

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

      Disconnect the airbag ECU assembly connector.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I58-13 (CANH) - I58-22 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR CAN BRANCH WIRE OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B002IWEC29
      *a

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I58-25 (E1) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
      I58-26 (E2) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    2. Reconnect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      I58-21 (IG2) - Body ground Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPAIR HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)