THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DTC Code DTC Name
Theft Warning Siren Circuit

DESCRIPTION

The theft warning siren has an internal battery. If the vehicle auxiliary battery cable is disconnected or any of the communication lines are open, the theft warning siren detects this and sounds its siren.

Although the theft warning siren usually sounds by receiving a signal from the main body ECU (multiplex network body ECU), the theft warning siren can sound by its internal battery in case the vehicle auxiliary battery cable is disconnected.

The main body ECU (multiplex network body ECU) sends an arming signal to the theft warning siren while transferring to the armed state, and it also sends a disarming signal to the siren while switching to the disarmed state. Also, the main body ECU (multiplex network body ECU) can cause the theft warning siren to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

B312497E17

CAUTION / NOTICE / HINT

Note:

  • If the theft warning siren assembly is replaced, refer to the Service Bulletin.

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

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE

  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN2)

    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Active Test.

    5. According to the display on the GTS, perform the Active Test.

      Body Electrical > Main Body > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      Security Horn2

      Theft warning siren

      ON or OFF

      -

      Body Electrical > Main Body > Active Test

      Tester Display

      Security Horn2

      OK

      The theft warning siren assembly sounds and stops correctly when operated through the GTS.

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND)

    1. B298276C02

      *a

      Front view of wire harness connector

      (to Theft Warning Siren Assembly)

      Disconnect the theft warning siren assembly connector.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      M8-5 (+B) - Body ground

      Power switch off

      11 to 14 V

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      M8-2 (GND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN ASSEMBLY - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])

    1. Disconnect the M8 theft warning siren assembly connector.

    2. Disconnect the G79 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      M8-4 (CONT) - G79-18 (SSCL)

      Always

      Below 1 Ω

      M8-4 (CONT) - Body ground

      Always

      10 kΩ or higher

      G79-18 (SSCL) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK THEFT WARNING SIREN ASSEMBLY

    1. Temporarily replace the theft warning siren assembly with a new or normally functioning one.

      Tip:

      Refer to the Service Bulletin.

    2. Check the operation of the theft warning siren assembly function.

      OK

      Theft warning siren assembly function operates normally.

    Result

    Proceed to

    OK

    NG
    OK

    END (THEFT WARNING SIREN ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here