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Home >> Toyota >> 2012 >> Prius Plug-in >> Repair and Diagnosis (Single Page) >> Restraints >> Restraints Control Systems >> Supplemental Restraint System (Plug-In) (Diagnostic Codes & Symptom Tests) >> Airbag System >> DTC B1820/55: Short in Side Squib RH Circuit; DTC B1821/55: Open in Side Squib RH Circuit; DTC B1822/55: Short to GND in Side Squib RH Circuit; DTC B1823/55: Short to B+ in Side Squib RH Circuit >> Procedure
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DTC B1820/55: Short in Side Squib RH Circuit; DTC B1821/55: Open in Side Squib RH Circuit; DTC B1822/55: Short to GND in Side Squib RH Circuit; DTC B1823/55: Short to B+ in Side Squib RH Circuit: Procedure

  1. CHECK CONNECTORS 
    1. Turn the power switch off.
      Fig 1: Identifying Airbag Sensor Connector
      GTY321174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 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 front seat airbag assembly RH and airbag ECU assembly.

      OK

      The connectors are properly connected.

      HINT: 

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

    4. Disconnect the connectors from the front seat airbag assembly RH and airbag ECU assembly.
    5. Check that the terminals of the connectors are not damaged.

      OK

      The terminals are not deformed or damaged.

    6. Check that the short spring for the No. 2 floor wire with the activation prevention mechanism is not deformed or damaged.

      OK

      The short spring is not deformed or damaged.

      TEXT IN ILLUSTRATION

      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  2. CHECK FRONT SEAT AIRBAG ASSEMBLY RH (SIDE SQUIB RH) 
    1. Connect the connector to the airbag ECU assembly.
      Fig 2: Checking Front Seat Airbag Assembly RH (Front Side Squib RH)
      GTY328879Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect SST (resistance 2.1 Ω) to connector C.
      WARNING:

      Never connect the tester to the front seat airbag assembly RH (side squib RH) 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 it.
      • Insert SST straight into the terminals of the connector.
      • SST: 09843-18061 
    3. Connect the cable to the negative (-) auxiliary battery terminal.
    4. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    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 .

      OK

      DTC B1820/55, B1821/55, B1822/55 or B1823/55 is not output.

      HINT: 

      Codes other than DTCs B1820/55, B1821/55, B1822/55 and B1823/55 may be output at this time, but they are not related to this check.

    8. Turn the power switch off.
    9. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

    10. Disconnect SST from connector C.
      TEXT IN ILLUSTRATION

      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly
      *a Front view of wire harness connector
      (to Front Seat Airbag Assembly RH)

    NG → See step   4 

    OK → See step   3 

  3. REPLACE FRONT SEAT AIRBAG ASSEMBLY RH. Refer to  REMOVAL 
  4. CHECK NO. 2 FLOOR WIRE 
    1. Disconnect the No. 2 floor wire from the airbag ECU assembly.
      Fig 3: Checking No. 2 Floor Wire
      GTY337734Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 Condition Specified Condition
        S4-1 (SFR+) - Body ground Power switch on (IG) Below 1 V
        S4-2 (SFR-) - 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.
        WARNING:

        Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

    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
        S4-1 (SFR+) - S4-2 (SFR-) 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
        S4-1 (SFR+) - Body ground Always 1 MΩ or higher
        S4-2 (SFR-) - 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 DIAGNOSIS SYSTEM .
      2. Measure the resistance according to the value(s) in the table below.

        Standard Resistance

        Tester Connection Condition Specified Condition
        S4-1 (SFR+) - S4-2 (SFR-) Always 1 MΩ or higher
      3. Restore the released activation prevention mechanism of connector B to the original condition.
        TEXT IN ILLUSTRATION

        *1 Front Seat Airbag Assembly RH
        *2 Airbag ECU Assembly
        *3 No. 2 Floor Wire
        *a Front view of wire harness connector
        (to Front Seat Airbag Assembly RH)

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK: Go to next step 

  5. CHECK DTC 
    1. Connect the connectors to the front seat airbag assembly RH and airbag ECU assembly.
      Fig 4: Identifying Airbag Sensor Connector
      GTY319562Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) auxiliary battery terminal.
    3. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    4. Turn the power switch off.
    5. Turn the power switch on (IG), and wait for at least 60 seconds.
    6. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1820/55, B1821/55, B1822/55 or B1823/55 is not output.

      HINT: 

      Codes other than DTCs B1820/55, B1821/55, B1822/55 and B1823/55 may be output at this time, but they are not related to this check.

      TEXT IN ILLUSTRATION

      *1 Front Seat Airbag Assembly RH
      *2 Airbag ECU Assembly

    NG → See step   6 

    OK → See step   7 

  6. REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL 
  7. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING