AIRBAG SYSTEM SRS Warning Light does not Come 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 engine 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 battery voltage drops, the voltage-increase circuit (DC-DC converter) functions to increase the voltage of the SRS to normal voltage.

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

B0065DLE25

CAUTION / NOTICE / HINT

Note


  • After turning the engine 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 BATTERY VOLTAGE


    1. Measure the voltage of the battery.

      Standard Voltage
      11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT CHARGING SYSTEM AND BATTERY Click here

    OK

  2. CHECK CONNECTOR


    1. Turn the engine 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 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.

    4. Disconnect the connector from the combination meter 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

    REPAIR OR REPLACE CONNECTOR

    OK

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


    1. B0065KSC20
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

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

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      O3-21 (IG+) - Body ground Engine switch on (IG) 11 to 14 V
      O3-22 (B) - Body ground Always 11 to 14 V

    4. Turn the engine switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O3-31 (ES) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE WIRE HARNESS

    OK

  4. 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. Disconnect the connector from the airbag ECU assembly.

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

    5. Turn the engine switch on (IG) and check the SRS warning light condition.

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

      Tech Tips

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

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here