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Home >> Toyota >> 2021 >> 4Runner TRD Pro >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System - Diagnostic Codes (B1690-B1905) & Symptom Tests >> Airbag System >> SRS Warning Light Remains ON [08/2015 - 08/2019] >> Procedure

SRS Warning Light Remains ON [08/2015 - 08/2019]: Procedure

  1. CHECK CAN COMMUNICATION SYSTEM 
    1. Check if a CAN communication DTC is output (Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2019] ).
      RESULT

      Result Proceed to
      DTC is not output A
      DTCs are output B

    Result: 

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

    (Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2015 - 08/2019] )

    Result: 

    See step  2

  2. CHECK BATTERY 
    1. Measure the voltage of the battery.

      Standard voltage

      11 to 14 V

    Result: 

    NG 

    REPLACE OR RECHARGE BATTERY 

    Result: 

    OK 

    See step  3

  3. CHECK CONNECTORS 
    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 center airbag sensor and combination meter.

      OK

      The connectors are properly connected.

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE OF CENTER AIRBAG SENSOR) 
    1. Disconnect the connectors from the center airbag sensor.
      GTY721958Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    3. Turn the ignition switch to ON.
    4. Operate all the components of the electrical system (defogger, wipers, headlights, heater blower, etc.).
    5. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      F33-21 (IG2) - F33-25 (E1) Ignition switch ON 11 to 14 V
      F33-21 (IG2) - F33-26 (E2) Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Center Airbag Sensor)

    Result: 

    NG 

    REPLACE INSTRUMENT PANEL WIRE 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE OF COMBINATION METER) 
    1. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
      GTY699391Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the F14 connector from the combination meter.
    3. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      F14-17 (IG+) - F14-20 (E1) Ignition switch ON 11 to 14 V
      F14-15 (B) - F14-20 (E1) Always 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Combination Meter)

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. CHECK SRS WARNING LIGHT (SHORT TO GROUND) 
    1. Turn the ignition switch off.
    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
    3. Connect the connector to the combination meter.
    4. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    5. Turn the ignition switch to ON.
    6. Check the SRS warning light condition.
      NOTE:

      Make sure that nobody is in the vehicle.

      OK

      After the primary check period, the SRS warning light goes off for approximately 10 seconds and then remains on.

      HINT: 

      The primary check period is approximately 6 seconds after the ignition switch is turned to ON.

    Result: 

    OK 

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    NG 

    GO TO METER / GAUGE SYSTEM 

    (Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] )