AIRBAG SYSTEM SRS Warning Light Remains ON

DESCRIPTION

The SRS warning light is located on the No. 1 meter ECU sub-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.

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

The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the center 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.

A malfunction in this circuit is not recorded in the center 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 center airbag sensor assembly to the No. 1 meter ECU sub-assembly through the CAN communication system.

WIRING DIAGRAM

A01GKCCE11

INSPECTION PROCEDURE

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.

  • When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected Click here.

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

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if a CAN communication DTC is output (for LHD) Click here.

    2. Check if a CAN communication DTC is output (for RHD) Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK BATTERY


    1. Turn the engine switch off.

    2. Measure the voltage of the battery.

      Standard voltage
      11 to 14 V

    NG

    CHECK AND REPLACE BATTERY OR CHARGING SYSTEM

    OK

  3. CHECK CONNECTORS


    1. Turn the engine switch off.

    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

    3. Check that the connectors are properly connected to the center airbag sensor assembly and No. 1 meter ECU sub-assembly.

      OK
      The connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  4. CHECK HARNESS AND CONNECTOR (CENTER AIRBAG SENSOR ASSEMBLY - BATTERY AND BODY GROUND)

    A01GJS5E18

    1. Disconnect the connector from the center airbag sensor assembly.

    2. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

    3. Turn the engine switch on (IG).

    4. Operate all 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
      L73-21 (IG2) - L73-25 (E1) Engine switch on (IG) 11 to 14 V
      L73-21 (IG2) - L73-26 (E2) Engine switch on (IG) 11 to 14 V

    6. Turn the engine switch off.

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

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      L73-25 (E1) - Body ground Always Below 1 Ω
      L73-26 (E2) - Body ground Always Below 1 Ω

    NG

    REPLACE HARNESS AND CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 METER ECU SUB-ASSEMBLY - BATTERY AND BODY GROUND)

    A01GNFHE13

    1. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

    2. Disconnect the L10 connector from the No. 1 meter ECU sub-assembly.

    3. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

    4. Turn the engine switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      L10-14 (IG2) - L10-17 (E2) Engine switch on (IG) 11 to 14 V

    6. Turn the engine switch off.

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

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      L10-17 (E2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK SRS WARNING LIGHT


    1. Turn the engine switch off.

    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

    3. Connect the connector to the No. 1 meter ECU sub-assembly.

    4. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

    5. Turn the engine switch on (IG).

    6. Check the SRS warning light condition.

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

      Tech Tips

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


    NG

    GO TO METER / GAUGE SYSTEM

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here