AIRBAG SYSTEM, Diagnostic DTC:B1617, B1618

DTC Code DTC Name
B1617 Front Airbag Sensor LH Lost Communication
B1618 Front Airbag Sensor LH Initialization

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.

These DTCs are stored when a malfunction is detected in the front airbag sensor LH circuit.

DTC No. DTC Detection Condition Trouble Area

B1617

B1618

  • The airbag ECU assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the front airbag sensor LH circuit.

  • Front airbag sensor LH malfunction

  • Airbag ECU assembly malfunction

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor LH

  • Airbag ECU assembly

WIRING DIAGRAM

A004IT0E55
*a BUSIN
*b RTNIN
*c Front Airbag SensorLH
*d Airbag ECU Assembly

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.

PROCEDURE


  1. CHECK CONNECTORS


    1. Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the airbag ECU assembly and front airbag sensor LH. Also check that the connectors that link the engine room main wire and instrument panel wire are properly connected.

      OK
      The connectors are properly connected.

      Tech Tips

      If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

    4. Disconnect the connectors from the airbag ECU assembly and front airbag sensor LH. Also disconnect the connectors that link the engine room main wire and instrument panel wire.

    5. Check that the terminals of the connectors are not damaged.

      OK
      The terminals are not deformed or damaged.

    NG

    REPLACE WIRE HARNESS

    OK

  2. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (OPEN)


    1. A004HK7E02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Service Wire
      *a

      Front view of wire harness connector

      (to Airbag ECU Assembly)
      *b

      Front view of wire harness connector

      (to Front Airbag Sensor LH)

      Connect the connectors that link the engine room main wire and instrument panel wire.

    2. 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 the wire.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-2 (BUSIN) - A58-1 (RTNIN) Always Below 1 Ω

    NG

    CHECK INSTRUMENT PANEL WIRE (OPEN) Click here

    OK

  3. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT)


    1. A004I4LE02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Front Airbag Sensor LH)

      Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-2 (BUSIN) - A58-1 (RTNIN) Always 1 MΩ or higher

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT) Click here

    OK

  4. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO B+)


    1. A004I4LE02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Front Airbag Sensor LH)

      Connect the cable to the negative (-) battery terminal.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A58-2 (BUSIN) - Body ground Ignition switch ON Below 1 V
      A58-1 (RTNIN) - Body ground Ignition switch ON Below 1 V

    4. Turn the ignition switch off.

    5. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.


    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT TO B+) Click here

    OK

  5. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT TO GROUND)


    1. A004I4LE02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Front Airbag Sensor LH)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-2 (BUSIN) - Body ground Always 1 MΩ or higher
      A58-1 (RTNIN) - Body ground Always 1 MΩ or higher

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND) Click here

    OK

  6. CHECK FRONT AIRBAG SENSOR LH


    1. A004H8SE01
      Text in Illustration
      *1 Front Airbag Sensor RH
      *2 Airbag ECU Assembly

      Connect the connector to the airbag ECU assembly.

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

    3. Connect the cable to the negative (-) battery terminal.

    4. Clear the DTCs stored in memory Click here.

    5. Turn the ignition switch off.

    6. Turn the ignition switch to ON, and wait for at least 60 seconds.

    7. Check for DTCs Click here.

      Result
      Result Proceed to
      DTCs B1612, B1613, B1617 and B1618 are not output. A
      DTC B1617 or B1618 is output. B
      DTC B1612 or B1613 is output. C

      Tech Tips

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

    8. Turn the ignition switch off.

    9. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

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


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE AIRBAG ECU ASSEMBLY Click here

    C

    REPLACE FRONT AIRBAG SENSOR LH Click here

  7. CHECK INSTRUMENT PANEL WIRE (OPEN)


    1. A004IG4E02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *5 Service Wire
      *a

      Front view of wire harness connector

      (to Airbag ECU Assembly)
      *b

      Front view of wire harness connector

      (to Engine Room Main Wire)

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

      Tech Tips

      The service wire has already been inserted into connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      DA3-4 - DA3-3 Always Below 1 Ω

    3. Disconnect the service wire from connector B.


    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  8. CHECK INSTRUMENT PANEL WIRE (SHORT)


    1. A004K26E02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Engine Room Main Wire)

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      DA3-4 - DA3-3 Always 1 MΩ or higher

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  9. CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)


    1. A004K26E02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Engine Room Main Wire)

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

    2. Connect the cable to the negative (-) battery terminal.

    3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      DA3-4 - Body ground Ignition switch ON Below 1 V
      DA3-3 - Body ground Ignition switch ON Below 1 V

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  10. CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)


    1. A004K26E02
      Text in Illustration
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Engine Room Main Wire)

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      DA3-4 - Body ground Always 1 MΩ or higher
      DA3-3 - Body ground Always 1 MΩ or higher

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE