AIRBAG SYSTEM, Diagnostic DTC:B1617/84, B1618/84

DTC Code DTC Name
B1617/84 Lost Communication with Front Airbag Sensor LH
B1618/84 Front Airbag Sensor LH Initialization Incomplete

DESCRIPTION

The front airbag sensor LH circuit consists of the airbag ECU assembly and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the airbag ECU assembly to determine if the airbag should be deployed.

DTC B1617/84 or B1618/84 is stored when a malfunction is detected in the front airbag sensor LH circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1617/84 Lost Communication with Front Airbag Sensor LH

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the front airbag sensor LH circuit for 2 seconds.

  • A front airbag sensor LH malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor LH

  • Airbag ECU assembly
B1618/84 Front Airbag Sensor LH Initialization Incomplete

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the front airbag sensor LH circuit for 2 seconds.

  • A front airbag sensor LH malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor LH

  • Airbag ECU assembly

WIRING DIAGRAM

B002K78E24
*a Front Airbag Sensor LH
*b Airbag ECU Assembly

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 CONNECTION OF CONNECTORS


    1. Turn the power switch off.

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

    3. Check that the connectors are properly connected to the airbag ECU assembly and front airbag sensor LH.

      Result
      Proceed to
      The connectors are properly connected
      The connectors are not properly connected

    The connectors are not properly connected

    CONNECT CONNECTORS PROPERLY

    The connectors are properly connected

  2. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly and front airbag sensor LH.

    2. B002IV5C10
      *1 Front Airbag Sensor LH
      *2 airbag ECU assembly

      Check that the connectors (on the airbag ECU assembly side and front airbag sensor LH side) are not damaged.

      Result
      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    The connectors are deformed or damaged

    REPLACE HARNESS AND CONNECTOR

    The connectors are not deformed or damaged

  3. CHECK FRONT AIRBAG SENSOR LH CIRCUIT


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

      B002JQAC03
      *1 Front Airbag Sensor LH *2 Airbag ECU Assembly
      *3 Connector E *4 Connector B
      *5 Service Wire - -
      *a

      Front view of wire harness connector

      (to Front Airbag Sensor LH)

      		 *b

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A14-2 (+SL) - Body ground Power switch on (IG) Below 1 V
      A14-1 (-SL) - Body ground Power switch on (IG) Below 1 V

    4. Turn the power switch off.

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

    6. Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.

      Note

      Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A14-2 (+SL) - A14-1 (-SL) Always Below 1 Ω

    8. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A14-2 (+SL) - A14-1 (-SL) Always 1 MΩ or higher
      A14-2 (+SL) - Body ground Always 1 MΩ or higher
      A14-1 (-SL) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK INSTRUMENT PANEL WIRE Click here

    OK

  4. CHECK FRONT AIRBAG SENSOR LH


    1. B002HG9C28
      *1 Front Airbag Sensor RH
      *2 Airbag ECU Assembly

      Connect the connectors to the airbag ECU assembly.

    2. Interchange the front airbag sensor LH with RH and connect the connectors to them.

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

    4. Turn the power switch on (IG), and wait for at least 60 seconds.

    5. Clear the DTCs stored in memory.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    6. Turn the power switch off.

    7. Turn the power switch on (IG), and wait for at least 60 seconds.

    8. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1617/84 or B1618/84 is output
      DTC B1612/83 or B1613/83 is output
      DTC B1612/83, B1613/83, B1617/84 and B1618/84 are not output

      Tech Tips

      Codes other than DTC B1612/83, B1613/83, B1617/84 and B1618/84 may be output at this time, but they are not related to this check.

    9. Turn the power switch off.

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

    11. Return the front airbag sensor RH and LH to their original positions and connect the connectors to them.


    DTC B1617/84 or B1618/84 is output

    REPLACE AIRBAG ECU ASSEMBLY Click here

    DTC B1612/83 or B1613/83 is output

    REPLACE FRONT AIRBAG SENSOR LH Click here

    DTC B1612/83, B1613/83, B1617/84 and B1618/84 are not output

    USE SIMULATION METHOD TO CHECK Click here

  5. CHECK INSTRUMENT PANEL WIRE


    1. Disconnect the instrument panel wire connector from the engine room main wire.

      B002HORC03
      *1 Front Airbag Sensor LH *2 Airbag ECU Assembly
      *3 Engine Room Main Wire *4 Instrument Panel Wire
      *5 Connector C *6 Connector B
      *7 Service Wire - -
      *a

      Front view of wire harness connector

      (to Engine Room Main Wire)

      		 *b

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

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

    3. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      AI10-1 (+SL) - Body ground Power switch on (IG) Below 1 V
      AI10-2 (-SL) - Body ground Power switch on (IG) Below 1 V

    5. Turn the power switch off.

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

    7. Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.

      Note

      Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      AI10-1 (+SL) - AI10-2 (-SL) Always Below 1 Ω

    9. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      AI10-1 (+SL) - AI10-2 (-SL) Always 1 MΩ or higher
      AI10-1 (+SL) - Body ground Always 1 MΩ or higher
      AI10-2 (-SL) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE