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Home >> Lexus >> 2022 >> LS 500h RWD >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System (W/O Advanced Park) - Diagnostic Codes (3 Of 3) >> AIRBAG SYSTEM (w/o Advanced Park) >> DTC B1805: Short in Front Passenger Squib Circuit; DTC B1806: Open in Front Passenger Squib Circuit; DTC B1807: Short to GND in Front Passenger Side Squib Circuit; DTC B1808: Short to B+ in Front Passenger Side Squib Circuit [10/2020 - 10/2023] >> Procedure

DTC B1805: Short in Front Passenger Squib Circuit; DTC B1806: Open in Front Passenger Squib Circuit; DTC B1807: Short to GND in Front Passenger Side Squib Circuit; DTC B1808: Short to B+ in Front Passenger Side Squib Circuit [10/2020 - 10/2023]: Procedure

  1. CHECK CONNECTORS 
    1. Turn the power switch off.
      GTY741782Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Instrument Panel Passenger without Door Airbag Assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 60 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the instrument panel passenger without door airbag assembly and airbag ECU assembly.

      OK

      The connectors are properly connected.

      HINT: 

      If the connectors are not properly connected, reconnect the connectors and proceed to the next inspection.

    4. Disconnect the connectors from the instrument panel passenger without door airbag 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 instrument panel wire connector (on the instrument panel passenger without door airbag 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 is not deformed or damaged.

      OK

      The short springs are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE INSTRUMENT PANEL WIRE 

    Result: 

    OK 

    See step  2

  2. CHECK INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY 
    1. Connect the instrument panel wire to the No. 2 instrument panel wire and airbag ECU assembly.
      GTY969066Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Instrument Panel Passenger without Door Airbag Assembly
      *2 Airbag ECU Assembly
      *3 Instrument Panel Wire
      *4 SST
      *a Front view of wire harness connector
      (to Instrument Panel Passenger without Door Airbag Assembly)
      *b Color: Orange
    2. Connect the white wire side of SST (resistance: 2.1 Ω) to connector C (orange connector).
      WARNING:

      Never connect the tester to the instrument panel passenger without door 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 
    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.

      Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

      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.

      Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Proceed to
      DTC B1805, B1806, B1807 and B1808 are not output
      DTC B1805, B1806, B1807 or B1808 is output

      HINT: 

      Codes other than DTC B1805, B1806, B1807 and B1808 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 60 seconds.
    11. Disconnect SST from connector C.

    Result: 

    DTC B1805, B1806, B1807 and B1808 are not output 

    REPLACE INSTRUMENT PANEL PASSENGER WITHOUT DOOR AIRBAG ASSEMBLY. Refer to  REMOVAL [10/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

    Result: 

    DTC B1805, B1806, B1807 or B1808 is output 

    See step  3

  3. CHECK FRONT PASSENGER SIDE SQUIB CIRCUIT 
    1. Disconnect the airbag ECU assembly connector.
      GTY793545Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Instrument Panel Passenger without Door Airbag Assembly
      *2 Airbag ECU Assembly
      *a Front view of wire harness connector
      (to Instrument Panel Passenger without Door Airbag Assembly)
      *b Color: Orange
      Release the activation prevention mechanism
    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
        G150-1 (P-) - Body ground Power switch on (IG) Below 1 V
        G150-2 (P+) - 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 60 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
        G150-1 (P-) - G150-2 (P+) 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
        G150-1 (P-) - Body ground Always 1 MΩ or higher
        G150-2 (P+) - 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.

        Refer to SYSTEM DESCRIPTION [10/2020 - 10/2023]

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

        Standard Resistance

        Tester Connection Condition Specified Condition
        G150-1 (P-) - G150-2 (P+) Always 1 MΩ or higher
      3. Restore the released activation prevention mechanism of connector B to the original condition.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE INSTRUMENT PANEL WIRE 

    Result: 

    OK 

    See step  4

  4. CHECK DTC 
    1. Connect the connectors to the instrument panel passenger without door airbag assembly and airbag ECU assembly.
      GTY968169Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Instrument Panel Passenger without Door Airbag Assembly
      *2 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.

      Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

      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.

      Refer to DTC CHECK / CLEAR [10/2020 - 10/2023]

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Proceed to
      DTC B1805, B1806, B1807 and B1808 are not output
      DTC B1805, B1806, B1807 or B1808 is output

      HINT: 

      Codes other than DTC B1805, B1806, B1807 and B1808 may be output at this time, but they are not related to this check.

    Result: 

    DTC B1805, B1806, B1807 and B1808 are not output 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - 11/2021]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 10/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 10/2023] 

    Result: 

    DTC B1805, B1806, B1807 or B1808 is output 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]