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 airbags and pretensioners should be deployed.

These DTCs are 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

Any of the following conditions is met:


  • The airbag ECU assembly detects a line short, short to ground or B+, or an open 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

 Does not apply to test/check mode
B1618/84 Front Airbag Sensor LH Initialization Incomplete

Any of the following conditions is met:


  • The airbag ECU assembly detects a line short, short to ground or B+, or an open 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

 Does not apply to test/check mode
DTC Detection Conditions: B1617/84
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3
Diagnosis Condition - - - -
Malfunction Status The airbag ECU assembly detects a line short, short to ground or B+, or an open in the front airbag sensor LH circuit. ○ - -
Front airbag sensor LH malfunction - ○ -
Airbag ECU assembly malfunction - - ○
Detection Time - - -
Number of Trips 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

DTC Detection Conditions: B1618/84
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3
Diagnosis Condition - - - -
Malfunction Status The airbag ECU assembly detects a line short, short to ground or B+, or an open in the front airbag sensor LH circuit ○ - -
Front airbag sensor LH malfunction - ○ -
Airbag ECU assembly malfunction - - ○
Detection Time - - -
Number of Trips 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

B002D1UE42
*a Front Airbag Sensor LH
*b Airbag ECU Assembly

CAUTION / NOTICE / HINT

Note


  • After turning the engine 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

  • After replacing the airbag ECU assembly, refer to initialization.

    Click here

PROCEDURE


  1. CHECK 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 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 properly connected, 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.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRE HARNESS

    OK

  2. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (OPEN)


    1. B002F1BC08
      *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
      A10-2 (+SL) - A10-1 (-SL) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    CHECK INSTRUMENT PANEL WIRE (OPEN) Click here

    OK

  3. CHECK FRONT AIRBAG SENSOR LH CIRCUIT (SHORT)


    1. B002C9TC20
      *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
      A10-2 (+SL) - A10-1 (-SL) Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT) Click here

    OK

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


    1. B002C9TC20
      *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 engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A10-2 (+SL) - Body ground Engine switch on (IG) Below 1 V
      A10-1 (-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.

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. B002C9TC20
      *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
      A10-2 (+SL) - Body ground Always 1 MΩ or higher
      A10-1 (-SL) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND) Click here

    OK

  6. CHECK FRONT AIRBAG SENSOR LH


    1. B002E5UC04
      *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


      Body Electrical > SRS Airbag > Clear DTCs

    5. Turn the engine switch off.

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

    7. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes

      Tech Tips

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

      Result
      Result Proceed to
      DTCs B1612/83, B1613/83, B1617/84 and B1618/84 are not output. A
      DTC B1617/84 or B1618/84 is output. B
      DTC B1612/83 or B1613/83 is output. C

    8. Turn the engine switch off.

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

    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 (SHORT TO GROUND)


    1. B002E3XC02
      *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
      KA2-1 (-SL) - Body ground Always 1 MΩ or higher
      KA2-2 (+SL) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

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


    1. B002E3XC02
      *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 engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      KA2-1 (-SL) - Body ground Engine switch on (IG) Below 1 V
      KA2-2 (+SL) - Body ground Engine switch on (IG) Below 1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  9. CHECK INSTRUMENT PANEL WIRE (SHORT)


    1. B002E3XC02
      *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
      KA2-1 (-SL) - KA2-2 (+SL) Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  10. CHECK INSTRUMENT PANEL WIRE (OPEN)


    1. B002DX7C01
      *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
      KA2-1 (-SL) - KA2-2 (+SL) Always Below 1 Ω

    3. Disconnect the service wire from connector B.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE