AIRBAG SYSTEM, Diagnostic DTC:B1617/84 and 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 center airbag sensor and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor 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

Test Mode / Check Mode

B1617/84

Lost Communication with Front Airbag Sensor LH

One of the following conditions is met:

  • The center airbag sensor 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.

  • A center airbag sensor malfunction.

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor LH

  • Center airbag sensor assembly

*1

B1618/84

Front Airbag Sensor LH Initialization Incomplete

One of the following conditions is met:

  • The center airbag sensor 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.

  • A center airbag sensor malfunction.

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor LH

  • Center airbag sensor assembly

*1

WIRING DIAGRAM

C213916E08

CAUTION / NOTICE / HINT

Note:

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (Click hereClick hereClick 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 hereClick hereClick hereClick here).

PROCEDURE

  1. CHECK CONNECTION OF CONNECTORS

    1. Turn the engine switch off.

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

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

      OK

      The connectors are properly connected.

      Result

      Result

      OK

      NG
    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK CONNECTORS

    1. C208241C03

      *1

      Front Airbag Sensor LH

      *2

      Center Airbag Sensor

      Disconnect the connectors from the center airbag sensor and front airbag sensor LH.

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

      OK

      The connectors are not deformed or damaged.

      Result

      Result

      OK

      NG
    NG

    REPLACE HARNESS AND CONNECTOR

    OK

  3. CHECK FRONT AIRBAG SENSOR LH CIRCUIT

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

      C214530C04

      *1

      Front Airbag Sensor LH

      *2

      Center Airbag Sensor

      *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 Center Airbag Sensor)

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      A18-2 (+SL) - Body ground

      Engine switch on (IG)

      Below 1 V

      A18-1 (-SL) - Body ground

      Engine switch on (IG)

      Below 1 V

    3. Turn the engine switch off.

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

    5. 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.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A18-2 (+SL) - A18-1 (-SL)

      Always

      Below 1 Ω

    7. Disconnect the service wire from connector B.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A18-2 (+SL) - A18-1 (-SL)

      Always

      1 MΩ or higher

      A18-2 (+SL) - Body ground

      Always

      1 MΩ or higher

      A18-1 (-SL) - Body ground

      Always

      1 MΩ or higher

      Result

      Result

      OK

      NG
    NG

    CHECK INSTRUMENT PANEL WIRE (CENTER AIRBAG SENSOR - ENGINE ROOM MAIN WIRE)Click here

    OK

  4. CHECK FRONT AIRBAG SENSOR LH

    1. C148689C12

      *1

      Front Airbag Sensor RH

      *2

      Center Airbag Sensor

      Connect the connectors to the center airbag sensor.

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

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

    4. Turn the engine 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 engine switch off.

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

    8. Check for DTCs.

      Click here

      Body Electrical > SRS Airbag > Trouble Codes

      Result

      Result

      Proceed to

      DTC B1617 or B1618 is output

      A

      DTC B1612 or B1613 is output

      B

      DTC B1612, B1613, B1617 and B1618 are not output

      C
      Tip:

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

    A

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY

    Click here

    B

    REPLACE FRONT AIRBAG SENSOR LH

    Click here

    C

    REPLACE USE SIMULATION METHOD TO CHECK

    Click here

  5. CHECK INSTRUMENT PANEL WIRE (CENTER AIRBAG SENSOR - ENGINE ROOM MAIN WIRE)

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

      C214531C02

      *1

      Front Airbag Sensor LH

      *2

      Center Airbag Sensor

      *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 Center Airbag Sensor)

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

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      GA4-3 (+SL) - Body

      Engine switch on (IG)

      Below 1 V

      GA4-4 (-SL) - Body ground

      Engine switch on (IG)

      Below 1 V

    4. Turn the engine switch off.

    5. Disconnect the cable from the negative (-) 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

      GA4-3 (+SL) - GA4-4 (-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

      GA4-3 (+SL) - GA4-4 (-SL)

      Always

      1 MΩ or higher

      GA4-3 (+SL) - Body ground

      Always

      1 MΩ or higher

      GA4-4 (-SL) - Body ground

      Always

      1 MΩ or higher

      Result

      Result

      OK

      NG
    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE