AIRBAG SYSTEM, Diagnostic DTC:B1800/51, B1801/51, B1802/51, B1803/51

DTC Code DTC Name
B1800/51 Short in Driver Side Squib Circuit
B1801/51 Open in Driver Side Squib Circuit
B1802/51 Short to GND in Driver Side Squib Circuit
B1803/51 Short to B+ in Driver Side Squib Circuit

DESCRIPTION

The driver side squib circuit consists of the airbag ECU assembly, spiral cable sub-assembly and horn button assembly. The airbag ECU assembly sends deployment signals to the driver side squib through this circuit when the deployment conditions are met.

The following DTCs are recorded in the memory when a malfunction is detected in the driver side squib circuit.

DTC No. DTC Detection Condition Trouble Area(s)
B1800/51 Short in the driver side squib circuit

  • Horn button assembly (Driver side squib)

  • Spiral cable sub-assembly

  • Airbag ECU assembly

  • Cowl wire
B1801/51 Open in the driver side squib circuit

  • Horn button assembly (Driver side squib)

  • Spiral cable sub-assembly

  • Airbag ECU assembly

  • Cowl wire
B1802/51 Short to ground in the driver side squib circuit

  • Horn button assembly (Driver side squib)

  • Spiral cable sub-assembly

  • Airbag ECU assembly

  • Cowl wire
B1803/51 Short to B+ in the driver side squib circuit

  • Horn button assembly (Driver side squib)

  • Spiral cable sub-assembly

  • Airbag ECU assembly

  • Cowl wire

WIRING DIAGRAM

A01KFEAE22

INSPECTION PROCEDURE

Tech Tips


  • If only past DTCs are indicated, perform troubleshooting using the symptom simulation method Click here.

  • Perform the simulation method by selecting the Check Mode (Signal Check) using the intelligent tester. After selecting the Check Mode (Signal Check), perform the simulation method by shaking each connector of the airbag system or driving the vehicle on on various roads, such as city roads and rough roads Click here.

  • Once the cause of the trouble has been eliminated, clear the DTCs which were stored during troubleshooting and then check for DTCs to confirm whether the system is sound Click here.

PROCEDURE


  1. CHECK CONNECTORS

    A01KGLYE02
    Text in Illustration
    *1 Cowl Wire
    *2 Horn Button Assembly
    *3 Spiral Cable Sub-assembly
    *4 Airbag ECU Assembly

    1. Turn the ignition 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 horn button assembly, the spiral cable sub-assembly and the airbag ECU assembly.

      OK
      The connectors are properly connected and secured.

      Tech Tips

      After confirming that the connectors are secured in the correct positions, proceed to the next check.

    4. Disconnect the connectors from the horn button assembly, the spiral cable sub-assembly and the airbag ECU assembly.

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

      OK
      The terminals are not damaged.

    6. Check that the short springs of the activation prevention mechanism are not damaged.

      OK
      The short springs are not damaged.

      Tech Tips

      The short springs are located in Connectors B, D and F.


    NG

    REPLACE WIRE HARNESSES AND COMPONENTS WITH DAMAGED CONNECTORS

    OK

  2. CHECK HORN BUTTON ASSEMBLY

    A01KGEFE02
    Text in Illustration
    *1 Cowl Wire
    *2 Horn Button Assembly
    *3 Spiral Cable Sub-assembly
    *4 Airbag ECU Assembly
    *a

    Front view of wire harness connector

    (to Horn Button Assembly)
    *b Connector E

    1. Confirm that the cable is disconnected from the negative (-) battery terminal.

    2. Connect the cowl wire to the airbag ECU assembly and the spiral cable sub-assembly.

    3. Connect SST (resistance 2.1 Ω) to Connector E.

      SST
      09843-18060

      CAUTION:

      Do not connect an electrical tester to the horn button assembly (Driver side squib) to measure the resistance. Accidental deployment of the SRS could lead to a serious injury.

      Note


      • Do not forcibly insert the SST into the connector. It may damage the terminals of the connector and cause an imperfect connection.

      • Align the pin of the SST with one of the terminals of the connector when connecting them.

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

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

    6. Clear the DTCs stored in the memory Click here.

    7. Turn the ignition switch off.

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

    9. Check for DTCs Click here.

      OK
      DTCs B1800, B1801, B1802, B1803 and 51 are not indicated.

      Tech Tips

      DTCs other than DTC B1800, B1801, B1802, B1803 and 51 may be indicated at this time, but they are not related to this check.


    NG

    CHECK DRIVER SQUIB CIRCUIT (AIRBAG ECU ASSEMBLY - HORN BUTTON ASSEMBLY) Click here

    OK

    REPLACE HORN BUTTON ASSEMBLY Click here

  3. CHECK DRIVER SQUIB CIRCUIT (AIRBAG ECU ASSEMBLY - HORN BUTTON ASSEMBLY)

    A01KHMXE02
    Text in Illustration
    *1 Cowl Wire
    *2 Horn Button Assembly
    *3 Spiral Cable Sub-assembly
    *4 Airbag ECU Assembly
    *a

    Rear view of wire harness connector

    (to Horn Button Assembly)
    *b Connector E

    1. Turn the ignition switch off.

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

    3. Disconnect SST from Connector E.

    4. Disconnect the connector from the airbag ECU assembly.

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

    6. Turn the ignition switch to ON.

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


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

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

    8. Turn the ignition switch off.

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

    10. Check for an open circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        D+ - D- Always Below 1 Ω

    11. Release the built-in activation prevention mechanism of Connector B Click here.

    12. 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
        D+ - Body ground Always 1 MΩ or higher
        D- - Body ground Always 1 MΩ or higher

    13. Check for a short between lines in the circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        D+ - D- Always 1 MΩ or higher

    14. Reset the activation prevention mechanism of Connector B to its normal state.


    NG

    CHECK COWL WIRE (AIRBAG ECU ASSEMBLY - SPIRAL CABLE SUB-ASSEMBLY) Click here

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

  4. CHECK COWL WIRE (AIRBAG ECU ASSEMBLY - SPIRAL CABLE SUB-ASSEMBLY)

    A01KIC6E02
    Text in Illustration
    *1 Cowl Wire
    *2 Horn Button Assembly
    *3 Spiral Cable Sub-assembly
    *4 Airbag ECU Assembly
    *a

    Rear view of wire harness connector

    (to Horn Button Assembly)
    *b Connector C

    1. Confirm that the cable is disconnected from the negative (-) battery terminal.

    2. Disconnect the connector of the cowl wire from the spiral cable sub-assembly.

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

    4. Turn the ignition switch to ON.

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


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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        A18-1(D+) - Body ground Ignition switch ON Below 1 V
        A18-2(D-) - Body ground Ignition switch ON Below 1 V

    6. Turn the ignition switch off.

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

    8. Check for an open circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A18-1(D+) - A18-2(D-) Always Below 1 Ω

    9. Release the built-in activation prevention mechanism of Connector B Click here.

    10. 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
        A18-1(D+) - Body ground Always 1 MΩ or higher
        A18-2(D-) - Body ground Always 1 MΩ or higher

    11. Check for a short between lines in the circuit.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A18-1(D+) - A18-2(D-) Always 1 MΩ or higher

    12. Reset the activation prevention mechanism of Connector B to its normal state.


    NG

    REPLACE COWL WIRE

    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here