AIRBAG SYSTEM, Diagnostic DTC:B1800, B1801, B1802, B1803

DTC Code DTC Name
B1800 Short in D Squib Circuit
B1801 Open in D Squib Circuit
B1802 Short in D Squib Circuit (to Ground)
B1803 Short in D Squib Circuit (to +B)

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
B1800

  • The airbag ECU assembly receives a line short circuit signal in the driver side squib circuit during primary check.

  • Spiral cable sub-assembly malfunction

  • Driver side squib malfunction

  • Airbag ECU assembly malfunction

  • Instrument panel wire

  • Spiral cable sub-assembly

  • Horn button assembly (Driver side squib)

  • Airbag ECU assembly
B1801

  • The airbag ECU assembly receives an open circuit signal in the driver side squib circuit.

  • Spiral cable sub-assembly malfunction

  • Driver side squib malfunction

  • Airbag ECU assembly malfunction
B1802

  • The airbag ECU assembly receives a short circuit to ground signal in the driver side squib circuit.

  • Spiral cable sub-assembly malfunction

  • Driver side squib malfunction

  • Airbag ECU assembly malfunction
B1803

  • The airbag ECU assembly receives a short circuit to B+ signal in the driver side squib circuit.

  • Spiral cable sub-assembly malfunction

  • Driver side squib malfunction

  • Airbag ECU assembly malfunction

WIRING DIAGRAM

A004HAQE01

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.

Tech Tips


  • Perform the simulation method by selecting check mode (Signal Check) using the GTS Click here.

  • After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city road or rough road Click here.

PROCEDURE


  1. CHECK CONNECTORS


    1. A004H66E01
      Text in Illustration
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly
      *4 Instrument Panel Wire

      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 horn button assembly, spiral cable sub-assembly and airbag ECU assembly.

      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 horn button assembly, spiral cable sub-assembly and airbag ECU assembly.

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

      OK
      The terminals are not deformed or damaged.

    6. Check that the spiral cable sub-assembly connector (on the horn button assembly side) is not damaged.

      OK
      The lock button is not disengaged, or the claw of the lock is not deformed or damaged.

    7. Check that the short springs for the instrument panel wire and spiral cable sub-assembly with the activation prevention mechanism are not deformed or damaged.

      OK
      The short springs are not deformed or damaged.

    NG

    REPLACE WIRE HARNESS

    OK

  2. CHECK HORN BUTTON ASSEMBLY (DRIVER SIDE SQUIB)


    1. A004HI9E02
      Text in Illustration
      *A w/o Dual Airbag
      *B w/ Dual Airbag
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)
      *b Color: Orange

      Connect the instrument panel wire to the airbag ECU assembly and spiral cable sub-assembly.

    2. Connect SST (resistance 2.1 Ω) to connector E (orange connector).

      CAUTION:

      Never connect the tester to the horn button assembly (driver side squib) for measurement, as this may lead to a serious injury due to airbag deployment.

      Note


      • Do not forcibly insert SST into the terminals of the connector when connecting it.

      • Insert SST straight into the terminals of the connector.

      SST
      09843-18061

    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.

      OK
      DTC B1800, B1801, B1802 or B1803 is not output.

      Tech Tips

      Codes other than DTCs B1800, B1801, B1802 and B1803 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. Disconnect SST from connector E.


    OK

    REPLACE HORN BUTTON ASSEMBLY Click here

    NG

  3. CHECK DRIVER SIDE SQUIB CIRCUIT


    1. A004I9UE02
      Text in Illustration
      *A w/o Dual Airbag
      *B w/ Dual Airbag
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)
      *b Color: Orange

      Disconnect the instrument panel wire from the airbag ECU assembly.

    2. Check for a short to B+ in the circuit.


      1. 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
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - Body ground Ignition switch ON Below 1 V
        z6-1 (D+) - Body ground Ignition switch ON Below 1 V
        Standard Voltage
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - Body ground Ignition switch ON Below 1 V
        z7-1 (D-) - 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.

    3. Check for an open in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - z6-1 (D+) Always Below 1 Ω
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - z7-1 (D-) Always Below 1 Ω

    4. Check for a short to ground in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - Body ground Always 1 MΩ or higher
        z6-1 (D+) - Body ground Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - Body ground Always 1 MΩ or higher
        z7-1 (D-) - Body ground Always 1 MΩ or higher

    5. Check for a short in the circuit.


      1. Release the activation prevention mechanism built into connector B Click here.

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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - z6-1 (D+) Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - z7-1 (D-) Always 1 MΩ or higher

      3. Restore the released activation prevention mechanism of connector B to the original condition.


    NG

    CHECK INSTRUMENT PANEL WIRE Click here

    OK

  4. CHECK DTC


    1. A004KMTE01
      Text in Illustration
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly

      Connect the connectors to the horn button assembly and airbag ECU assembly.

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

    3. Clear the DTCs stored in memory Click here.

    4. Turn the ignition switch off.

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

    6. Check for DTCs Click here.

      OK
      DTC B1800, B1801, B1802 or B1803 is not output.

      Tech Tips

      Codes other than DTCs B1800, B1801, B1802 and B1803 may be output at this time, but they are not related to this check.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIRBAG ECU ASSEMBLY Click here

  5. CHECK INSTRUMENT PANEL WIRE


    1. A004IYNE02
      Text in Illustration
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Spiral Cable Sub-assembly)

      Disconnect the instrument panel wire from the spiral cable sub-assembly.

    2. Check for a short to B+ in the circuit.


      1. 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
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        D52-3 (D+) - Body ground Ignition switch ON Below 1 V
        D52-4 (D-) - Body ground Ignition switch ON Below 1 V
        Standard Voltage
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        D52-1 (D-) - Body ground Ignition switch ON Below 1 V
        D52-2 (D+) - 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.

    3. Check for an open in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        D52-3 (D+) - D52-4 (D-) Always Below 1 Ω
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        D52-1 (D-) - D52-2 (D+) Always Below 1 Ω

    4. Check for a short to ground in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        D52-3 (D+) - Body ground Always 1 MΩ or higher
        D52-4 (D-) - Body ground Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        D52-1 (D-) - Body ground Always 1 MΩ or higher
        D52-2 (D+) - Body ground Always 1 MΩ or higher

    5. Check for a short in the circuit.


      1. Release the activation prevention mechanism built into connector B Click here.

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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        D52-3 (D+) - D52-4(D-) Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        D52-1 (D-) - D52-2 (D+) Always 1 MΩ or higher

      3. Restore the released activation prevention mechanism of connector B to the original condition.


    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  6. CHECK SPIRAL CABLE SUB-ASSEMBLY


    1. A004HBME02
      Text in Illustration
      *A w/o Dual Airbag
      *B w/ Dual Airbag
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)
      *b Color: Orange

      Check for a short to B+ in the circuit.


      1. 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
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - Body ground Ignition switch ON Below 1 V
        z6-1 (D+) - Body ground Ignition switch ON Below 1 V
        Standard Voltage
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - Body ground Ignition switch ON Below 1 V
        z7-1 (D-) - 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.

    2. Check for an open in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - z6-1 (D+) Always Below 1 Ω
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - z7-1 (D-) Always Below 1 Ω

    3. Check for a short to ground in the circuit.


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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - Body ground Always 1 MΩ or higher
        z6-1 (D+) - Body ground Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - Body ground Always 1 MΩ or higher
        z7-1 (D-) - Body ground Always 1 MΩ or higher

    4. Check for a short in the circuit.


      1. Release the activation prevention mechanism built into connector D Click here.

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

        Standard Resistance
        w/o Dual Airbag
        Tester Connection Condition Specified Condition
        z6-2 (D-) - z6-1 (D+) Always 1 MΩ or higher
        Standard Resistance
        w/ Dual Airbag
        Tester Connection Condition Specified Condition
        z7-2 (D+) - z7-1 (D-) Always 1 MΩ or higher

      3. Restore the released activation prevention mechanism of connector D to the original condition.


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here