PEDESTRIAN PROTECTION 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 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, DTCs are output by the blinking of the SRS warning light.

The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the pedestrian detection 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 recorded in the pedestrian detection 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 pedestrian detection ECU assembly to the combination meter assembly through the CAN communication system.

WIRING DIAGRAM

B005UZHE03

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

  • 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 procedure.

  • When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

PROCEDURE


  1. CHECK BATTERY VOLTAGE


    1. Measure the battery voltage.

      Standard voltage
      11 to 14 V

      Tech Tips

      It may be possible to tell whether the battery is discharged by operating the horn.

      If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE OR RECHARGE BATTERY

    OK

  2. CHECK CONNECTOR


    1. Turn the engine switch off.

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

    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 HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BATTERY AND BODY GROUND)


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

    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
      G34-21 (IG+) - Body ground Engine switch on (IG) 10.5 to 16 V
      G34-22 (B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G34-31 (ES) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK SRS WARNING LIGHT


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

    2. Connect the connector to the combination meter assembly.

    3. Disconnect the connector from the pedestrian detection ECU assembly.

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

    5. Turn the engine 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 engine switch is turned on (IG).

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE PEDESTRIAN DETECTION ECU ASSEMBLY Click here

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here