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


DTC Code DTC Detection Condition Trouble Area
B1800

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 cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Spiral cable sub-assembly

  • Horn button assembly (driver side squib)

  • Airbag ECU assembly
B1801

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 cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.
B1802

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 cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.
B1803

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 cable sub-assembly malfunction.

  • An airbag ECU assembly malfunction.

WIRING DIAGRAM

A01CJHFE05

INSPECTION PROCEDURE

Note


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

  • After turning the ignition 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 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.

Tech Tips

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

PROCEDURE


  1. CHECK HORN BUTTON ASSEMBLY (DRIVER SIDE SQUIB)


    1. Turn the ignition switch off.

      A01CGPWE02
      Text in Illustration
      *1 Horn Button Assembly *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly *4 Connector E
      *5 SST - -
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)

      		 *b Color: Orange

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

    3. Disconnect the connector from the horn button assembly.

    4. Connect the white wire of SST (resistance: 2.1 Ω) to connector E (orange 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

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

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

    7. Clear the DTCs stored in memory Click here.

    8. Turn the ignition switch off.

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

    10. 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.

    11. Turn the ignition switch off.

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

    13. Disconnect SST from connector E.


    NG

    CHECK CONNECTORS Click here

    OK

    REPLACE HORN BUTTON ASSEMBLY Click here

  2. CHECK CONNECTORS


    1. A01CHAQE01
      Text in Illustration
      *1 Horn Button Assembly
      *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly

      Disconnect the connector from the airbag ECU assembly.

    2. Check that the connectors (on the horn button assembly side and airbag ECU assembly side) are not damaged.

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

    NG

    REPLACE HARNESS AND CONNECTOR

    OK

  3. CHECK DRIVER SIDE SQUIB CIRCUIT


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

      A01CIFIE02
      Text in Illustration
      *1 Horn Button Assembly *2 Spiral Cable Sub-assembly
      *3 Airbag ECU Assembly *4 Connector E
      *a

      Front view of wire harness connector

      (to Horn Button Assembly)

      		 *b Color: Orange

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D36-2 (D+) - Body ground Ignition switch ON Below 1 V
      D36-1 (D-) - Body ground Ignition switch ON Below 1 V

    4. Turn the ignition switch off.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D36-2 (D+) - D36-1 (D-) Always Below 1 Ω

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D36-2 (D+) - D36-1 (D-) Always 1 MΩ or higher
      D36-2 (D+) - Body ground Always 1 MΩ or higher
      D36-1 (D-) - Body ground Always 1 MΩ or higher

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


    NG

    CHECK INSTRUMENT PANEL WIRE Click here

    OK

  4. CHECK AIRBAG ECU ASSEMBLY


    1. A01CGKZE02
      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, and wait at least 2 seconds.

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

    4. Clear the DTCs stored in memory Click here.

    5. Turn the ignition switch off.

    6. Turn the ignition switch to ON, and wait 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.


    NG

    REPLACE AIRBAG ECU ASSEMBLY Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  5. CHECK INSTRUMENT PANEL WIRE


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

      A01CH33E01
      Text in Illustration
      *1 Horn Button Assembly *2 Instrument Panel Wire
      *3 Spiral Cable Sub-assembly *4 Airbag ECU Assembly
      *5 Connector C - -
      *a

      Rear view of wire harness connector

      (to Spiral Cable Sub-assembly)

      		 - -

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

    3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      S35-1 (D+) - Body ground Ignition switch ON Below 1 V
      S35-2 (D-) - Body ground Ignition switch ON Below 1 V

    5. Turn the ignition switch off.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S35-1 (D+) - S35-2 (D-) Always Below 1 Ω

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S35-1 (D+) - S35-2 (D-) Always 1 MΩ or higher
      S35-1 (D+) - Body ground Always 1 MΩ or higher
      S35-2 (D-) - Body ground Always 1 MΩ or higher

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


    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here