AIRBAG SYSTEM, Diagnostic DTC:B1860/64, B1861/64, B1862/64, B1863/64

DTC Code DTC Name
B1860/64 Short in Driver Side Knee Airbag Squib Circuit
B1861/64 Open in Driver Side Knee Airbag Squib Circuit
B1862/64 Short to GND in Driver Side Knee Airbag Squib Circuit
B1863/64 Short to B+ in Driver Side Knee Airbag Squib Circuit

DESCRIPTION

The driver side knee squib circuit consists of the airbag ECU assembly and lower No. 1 instrument panel airbag assembly.

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

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

DTC No. Detection Item DTC Detection Condition Trouble Area
B1860/64 Short in Driver Side Knee Airbag 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 knee squib circuit during the primary check.

  • A lower No. 1 instrument panel airbag assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Lower No. 1 instrument panel airbag assembly

  • Airbag ECU assembly
B1861/64 Open in Driver Side Knee Airbag Squib Circuit

One of the following conditions is met:


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

  • A lower No. 1 instrument panel airbag assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Lower No. 1 instrument panel airbag assembly

  • Airbag ECU assembly
B1862/64 Short to GND in Driver Side Knee Airbag Squib Circuit

One of the following conditions is met:


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

  • A lower No. 1 instrument panel airbag assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Lower No. 1 instrument panel airbag assembly

  • Airbag ECU assembly
B1863/64 Short to B+ in Driver Side Knee Airbag Squib Circuit

One of the following conditions is met:


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

  • A lower No. 1 instrument panel airbag assembly malfunction.

  • An airbag ECU assembly malfunction.

  • Instrument panel wire

  • Lower No. 1 instrument panel airbag assembly

  • Airbag ECU assembly

WIRING DIAGRAM

B00599AE95
*a Lower No. 1 Instrument Panel Airbag Assembly
*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

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 LOWER NO. 1 INSTRUMENT PANEL AIRBAG ASSEMBLY


    1. B0059DLC09
      *1 Lower No. 1 Instrument Panel Airbag Assembly
      *2 Airbag ECU Assembly
      *3 Connector C
      *4 SST
      *a

      Front view of wire harness connector

      (to Lower No. 1 Instrument Panel Airbag Assembly)

      Turn the engine switch off.

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

    3. Disconnect the connector from the lower No. 1 instrument panel airbag assembly.

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

      CAUTION:

      Never connect the tester to the lower No. 1 instrument panel airbag 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 for at least 2 seconds.

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

    7. Clear the DTCs.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    8. Turn the engine switch off.

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

    10. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output
      DTC B1860/64, B1861/64, B1862/64 or B1863/64 is output

      Tech Tips

      Codes other than DTC B1860/64, B1861/64, B1862/64 and B1863/64 may be output at this time, but they are not related to this check.

    11. Turn the engine switch off.

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

    13. Disconnect SST from connector C.


    DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output

    REPLACE LOWER NO. 1 INSTRUMENT PANEL AIRBAG ASSEMBLY Click here

    DTC B1860/64, B1861/64, B1862/64 or B1863/64 is output

  2. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly.

    2. B0058JYC06
      *1 Lower No. 1 Instrument Panel Airbag Assembly
      *2 Instrument Panel Wire
      *3 Airbag ECU Assembly

      Check that the connectors (on the airbag ECU assembly side and lower No. 1 instrument panel airbag assembly side) are not damaged.

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

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  3. CHECK INSTRUMENT PANEL WIRE


    1. B005AMLC10
      *1 Lower No. 1 Instrument Panel Airbag Assembly
      *2 Instrument Panel Wire
      *3 Airbag ECU Assembly
      *4 Connector C
      *a

      Front view of wire harness connector

      (to Lower No. 1 Instrument Panel Airbag Assembly)

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

    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
      I18-1 (DK+) - Body ground Engine switch on (IG) Below 1 V
      I18-2 (DK-) - 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.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-1 (DK+) - I18-2 (DK-) 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
      I18-1 (DK+) - I18-2 (DK-) Always 1 MΩ or higher

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-1 (DK+) - Body ground Always 1 MΩ or higher
      I18-2 (DK-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INSTRUMENT PANEL WIRE

    OK

  4. CHECK DTC


    1. B0058J8C07
      *1 Lower No. 1 Instrument Panel Airbag Assembly
      *2 Airbag ECU Assembly

      Connect the connectors to the lower No. 1 instrument panel airbag assembly and airbag ECU assembly.

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

    3. Turn the engine 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 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
      Result
      Proceed to
      DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output
      DTC B1860/64, B1861/64, B1862/64 or B1863/64 is output

      Tech Tips

      Codes other than DTC B1860/64, B1861/64, B1862/64 and B1863/64 may be output at this time, but they are not related to this check.


    DTC B1860/64, B1861/64, B1862/64 or B1863/64 is not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1860/64, B1861/64, B1862/64 or B1863/64 is output

    REPLACE AIRBAG ECU ASSEMBLY Click here