AIRBAG SYSTEM SRS Warning Light Remains ON

DESCRIPTION

The SRS warning light is located in the combination meter assembly.

When the SRS is normal, the SRS warning light comes on for approximately 6 seconds after the ignition switch is turned from off to ON, and then goes off automatically.

If there is a malfunction in the SRS, the SRS warning light comes on to inform the driver of a problem.

When terminals TC and CG of the DLC3 are connected, DTCs are displayed by blinking of the SRS warning light.

The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the airbag sensor assembly in case the source voltage drops.

When the battery voltage drops, the voltage-increase circuit (DC-DC converter) functions to increase the voltage of the SRS to normal voltage. In addition, when the voltage drops, the SRS warning light will illuminate.

A malfunction in this circuit is not stored in the airbag sensor assembly. The SRS warning light automatically goes off when the source voltage returns to normal.

The signal to illuminate the SRS warning light is transmitted from the airbag sensor assembly to the combination meter assembly via the CAN communication system.

WIRING DIAGRAM

A01LY7JE03

CAUTION / NOTICE / HINT

Note


  • After turning the ignition 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

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE


  1. CHECK SRS WARNING LIGHT OPERATION


    1. Check the SRS warning light operation approximately 6 seconds after the ignition switch is turned to ON.

      Result
      SRS Warning Light Illumination Proceed to
      Remains on A
      Goes off and then comes on again B

    B
    A
  2. CHECK BATTERY VOLTAGE


    1. Measure the voltage of the battery.

      Standard Voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK CONNECTOR


    1. Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    3. Check that the connector is properly connected to the airbag sensor assembly.

      OK
      The connector is properly connected.

      Tech Tips

      If the connector is not properly connected, reconnect the connector and proceed to the next inspection.

    4. Disconnect the connector from the airbag sensor assembly.

    5. Check that the terminal of the connector is not damaged.

      OK
      The terminal is not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. CHECK WIRE HARNESS (AIRBAG SENSOR ASSEMBLY - BODY GROUND)


    1. A01LXG0C07
      *a

      Front view of wire harness connector

      (to Airbag Sensor Assembly)

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

    2. Turn the ignition switch to ON.

    3. Operate all components of the electrical systems (defogger, wipers, headlights, heater blower, etc.).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E14-21 (IG2) - Body ground Ignition switch ON 8 to 16 V
    5. Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E14-25 (E1) - Body ground Always Below 1 Ω
      E14-26 (E2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  5. CHECK SRS WARNING LIGHT


    1. Turn the ignition switch to ON.

    2. Check the SRS warning light condition.

      OK
      After the primary check period, the SRS warning light goes off for approximately 10 seconds and turns back on.

      Tech Tips

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

      Result
      Proceed to
      OK
      NG

    OK
    NG
  6. CHECK CAN COMMUNICATION SYSTEM


    1. Using the GTS, check if the CAN communication system is functioning normally.

      Tech Tips


      • Refer to Bus Check for the CAN communication system.

        Click here

      • The airbag sensor assembly is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.

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

    B
    A
  7. CHECK BATTERY VOLTAGE


    1. Measure the voltage of the battery.

      Standard Voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  8. CHECK CONNECTOR


    1. Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    3. Check that the connector is properly connected to the airbag sensor assembly.

      OK
      The connector is properly connected.

      Tech Tips

      If the connector is not properly connected, reconnect the connector and proceed to the next inspection.

    4. Disconnect the connector from the airbag sensor assembly.

    5. Check that the terminal of the connector is not damaged.

      OK
      The terminal is not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  9. CHECK WIRE HARNESS (AIRBAG SENSOR ASSEMBLY - BODY GROUND)


    1. A01LXG0C07
      *a

      Front view of wire harness connector

      (to Airbag Sensor Assembly)

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

    2. Turn the ignition switch to ON.

    3. Operate all components of the electrical system (defogger, wipers, headlights, heater blower, etc.).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E14-21 (IG2) - Body ground Ignition switch ON 8 to 16 V
    5. Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E14-25 (E1) - Body ground Always Below 1 Ω
      E14-26 (E2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  10. CHECK CONNECTOR


    1. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    2. Check that the connector is properly connected to the combination meter assembly.

      OK
      The connector is properly connected.

      Tech Tips

      If the connector is not properly connected, reconnect the connector and proceed to the next inspection.

    3. Disconnect the connector from the combination meter assembly.

    4. Check that the terminal of the connector is not damaged.

      OK
      The terminal is not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  11. CHECK WIRE HARNESS (COMBINATION METER ASSEMBLY - BODY GROUND)


    1. A01LW1UC04
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

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

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E46-39 (IG+) - Body ground Ignition switch ON 11 to 14 V
      E46-40 (B) - Body ground Always 11 to 14 V
    4. Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E46-21 (ET) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  12. CHECK SRS WARNING LIGHT


    1. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    2. Connect the connector to the combination meter assembly.

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

    4. Turn the ignition switch to ON.

    5. Check the SRS warning light condition.

      OK
      After the primary check period, the SRS warning light goes off for approximately 10 seconds and turns back on.

      Tech Tips

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

      Result
      Proceed to
      OK
      NG

    OK
    NG