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

DTC Code DTC Name
B1800 Short in Driver Squib Circuit
B1801 Open in Driver Squib Circuit
B1802 Short to GND in Driver Side Squib Circuit
B1803 Short to B+ in Driver Side Squib Circuit

DESCRIPTION

The driver side squib circuit consists of the airbag ECU assembly, spiral with sensor cable sub-assembly and horn button assembly.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the driver side squib circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Test Mode / Check Mode
B1800 Short in Driver Squib Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal 5 times in the driver side squib circuit during the primary check.

  • A horn button assembly malfunction.

  • A spiral with sensor cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Spiral with sensor cable sub-assembly

  • Horn button assembly

  • Airbag ECU assembly

 Comes on Applicable
B1801 Open in Driver Squib Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects an open circuit signal in the driver side squib circuit for 2 seconds.

  • A horn button assembly malfunction.

  • A spiral with sensor cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Spiral with sensor cable sub-assembly

  • Horn button assembly

  • Airbag ECU assembly

 Comes on Applicable
B1802 Short to GND in Driver Side Squib Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects a short circuit to ground signal in the driver side squib circuit for 0.5 seconds.

  • A horn button assembly malfunction.

  • A spiral with sensor cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Spiral with sensor cable sub-assembly

  • Horn button assembly

  • Airbag ECU assembly

 Comes on Applicable
B1803 Short to B+ in Driver Side Squib Circuit

One of the following conditions is met:


  • The airbag ECU assembly detects a short circuit to B+ signal in the driver side squib circuit for 0.5 seconds.

  • A horn button assembly malfunction.

  • A spiral with sensor cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Spiral with sensor cable sub-assembly

  • Horn button assembly

  • Airbag ECU assembly

 Comes on Applicable

WIRING DIAGRAM

B004TWLE40

CAUTION / NOTICE / HINT

Note


  • When installing the spiral with sensor cable sub-assembly and steering wheel, be sure to adjust the spiral with sensor cable sub-assembly as it may break if the steering wheel is turned before adjusting the spiral with sensor cable sub-assembly.

    Click here

  • 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

Tech Tips

To perform the simulation method, enter check mode (signal check) with the GTS (Click here ), and then wiggle each connector of the airbag system or drive the vehicle on various types of road Click here.

PROCEDURE


  1. CHECK CONNECTORS


    1. B004URCC01
      *1 Horn Button Assembly
      *2 Airbag ECU Assembly
      *3 Spiral with Sensor Cable Sub-assembly
      *4 Instrument Panel Wire

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

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

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

      OK
      The terminals are not deformed or damaged.

    6. Check that the spiral with sensor cable sub-assembly connector (on the horn button assembly side) is not loose, deformed or damaged.

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

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

      OK
      The short springs are not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INSTRUMENT PANEL WIRE OR SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

    OK

  2. CHECK HORN BUTTON ASSEMBLY


    1. B004UHAC17
      *1 Horn Button Assembly
      *2 Airbag ECU Assembly
      *3 Spiral with Sensor Cable Sub-assembly
      *4 SST
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)
      *b Color: Light Green

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

    2. Connect the white wire side of SST (resistance: 2.1 Ω) to connector E (light green connector).

      CAUTION:

      Never connect the tester to the horn button assembly 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 SST.

      • Insert SST straight into the terminals of the connector.

      SST
      09843-18061

    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.

      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 B1800, B1801, B1802 and B1803 are not output
      DTC B1800, B1801, B1802 or B1803 is output

      Tech Tips

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


    DTC B1800, B1801, B1802 and B1803 are not output

    REPLACE HORN BUTTON ASSEMBLY Click here

    DTC B1800, B1801, B1802 or B1803 is output

  3. CHECK DRIVER SIDE SQUIB CIRCUIT


    1. B004XYMC02
      *1 Horn Button Assembly
      *2 Airbag ECU Assembly
      *3 Spiral with Sensor Cable Sub-assembly
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)
      *b Color: Light Green
      B004SZX Release the activation prevention mechanism

      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 (-) auxiliary battery terminal, and wait for at least 2 seconds.

      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
        z3-2 (D+) - Body ground Power switch on (IG) Below 1 V
        z3-1 (D-) - 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.

    3. Check for an open in the circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        z3-2 (D+) - z3-1 (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
        Tester Connection Condition Specified Condition
        z3-2 (D+) - Body ground Always 1 MΩ or higher
        z3-1 (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
        Tester Connection Condition Specified Condition
        z3-2 (D+) - z3-1 (D-) Always 1 MΩ or higher

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

      Result
      Proceed to
      OK
      NG

    NG

    CHECK INSTRUMENT PANEL WIRE Click here

    OK

  4. CHECK DTC


    1. B004SWTC01
      *1 Horn Button Assembly
      *2 Airbag ECU Assembly
      *3 Spiral with Sensor Cable Sub-assembly

      Connect the connectors to the horn button assembly and 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), and wait for at least 60 seconds.

    4. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    5. Turn the power switch off.

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

    7. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1800, B1801, B1802 and B1803 are not output
      DTC B1800, B1801, B1802 or B1803 is output

      Tech Tips

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


    DTC B1800, B1801, B1802 and B1803 are not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1800, B1801, B1802 or B1803 is output

    REPLACE AIRBAG ECU ASSEMBLY Click here

  5. CHECK INSTRUMENT PANEL WIRE


    1. B004TXMC06
      *1 Horn Button Assembly
      *2 Airbag ECU Assembly
      *3 Spiral with Sensor Cable Sub-assembly
      *4 Instrument Panel Wire
      *a

      Front view of wire harness connector

      (to Spiral with Sensor Cable Sub-assembly)
      B004SZX Release the activation prevention mechanism

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

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


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

      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
        G 26-1 (D+) - Body ground Power switch on (IG) Below 1 V
        G 26-2 (D-) - 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.

    3. Check for an open in the circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        G 26-1 (D+) - G 26-2 (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
        Tester Connection Condition Specified Condition
        G 26-1 (D+) - Body ground Always 1 MΩ or higher
        G 26-2 (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
        Tester Connection Condition Specified Condition
        G 26-1 (D+) - G 26-2 (D-) Always 1 MΩ or higher

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

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY Click here

    NG

    REPLACE INSTRUMENT PANEL WIRE