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 power switch is turned from off to on (IG), 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.

If a malfunction occurs in the airbag ECU assembly, combination meter assembly or wire harness connected to the airbag ECU assembly or combination meter assembly, the SRS warning light comes on.

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 ECU assembly in case the source voltage drops.

When the auxiliary 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 ECU 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 ECU assembly to the combination meter assembly via CAN communication.

WIRING DIAGRAM

B004R0BE50

CAUTION / NOTICE / HINT

Note


  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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. Turn the power switch on (IG) and check the SRS warning light condition.

      Tech Tips

      The primary check is performed for approximately 6 seconds after the power switch is turned on (IG).

      Result
      Result Proceed to
      After the primary check period, the SRS warning light remains on. A
      After the primary check period, the SRS warning light goes off and comes on again. B

    B

    CHECK CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK AUXILIARY BATTERY VOLTAGE


    1. Measure the voltage of the auxiliary battery with the power switch off.

      Standard Voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT CHARGING SYSTEM AND AUXILIARY BATTERY Click here

    OK

  3. CHECK CONNECTOR


    1. Turn the power switch off.

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

      CAUTION:

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

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

    5. Check that the terminals of the connector are not deformed or damaged.

      OK
      The terminals are not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRE HARNESS

    OK

  4. CHECK WIRE HARNESS (AIRBAG ECU ASSEMBLY - BODY GROUND)


    1. B004Q5YC41
      *a

      Front view of wire harness connector

      (to Airbag ECU Assembly)

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

    2. Turn the power switch on (IG).

    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
      F56-21 (IG2) - Body ground Power switch on (IG) 8 to 16 V

    5. Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-25 (E1) - Body ground Always Below 1 Ω
      F56-26 (E2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRE HARNESS

    OK

  5. CHECK SRS WARNING LIGHT


    1. Turn the power switch on (IG) and check the SRS warning light condition.

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

      Tech Tips

      The primary check period is approximately 6 seconds after the power switch is turned on (IG).

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPLACE METER CIRCUIT PLATE Click here

  6. CHECK CAN COMMUNICATION SYSTEM


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

      OK
      CAN communication system is functioning normally.

      Tech Tips

      Refer to CAN Bus Check in CAN Communication System.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    GO TO CAN COMMUNICATION SYSTEM Click here

    OK

  7. CHECK AUXILIARY BATTERY VOLTAGE


    1. Measure the voltage of the auxiliary battery with the power switch off.

      Standard Voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT CHARGING SYSTEM AND AUXILIARY BATTERY Click here

    OK

  8. CHECK CONNECTOR


    1. Turn the power switch off.

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

      CAUTION:

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

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

    5. Check that the terminals of the connector are not deformed or damaged.

      OK
      The terminals are not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRE HARNESS

    OK

  9. CHECK WIRE HARNESS (AIRBAG ECU ASSEMBLY - BODY GROUND)


    1. B004Q5YC41
      *a

      Front view of wire harness connector

      (to Airbag ECU Assembly)

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

    2. Turn the power switch on (IG).

    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
      F56-21 (IG2) - Body ground Power switch on (IG) 8 to 16 V

    5. Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-25 (E1) - Body ground Always Below 1 Ω
      F56-26 (E2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE WIRE HARNESS

    OK

  10. CHECK CONNECTOR


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

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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 terminals of the connector are not deformed or damaged.

      OK
      The terminals are not deformed or damaged.
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CONNECTOR

    OK

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


    1. B004PFBC34
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      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
      F6-21 (IG+) - Body ground Power switch on (IG) 11 to 14 V
      F6-22 (B) - Body ground Power switch off 11 to 14 V

    4. Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F6-28 (ES) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE WIRE HARNESS

    OK

  12. CHECK SRS WARNING LIGHT


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

      CAUTION:

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

    2. Connect the connector to the combination meter assembly.

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

    4. Turn the power switch on (IG) and check the SRS warning light condition.

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

      Tech Tips

      The primary check period is approximately 6 seconds after the power switch is turned on (IG).

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPLACE METER CIRCUIT PLATE Click here