THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DTC Code DTC Name
Theft Warning Siren Circuit

DESCRIPTION

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

  • Although the theft warning siren (self power siren) usually sounds by receiving a signal from the main body ECU (instrument panel junction block assembly), the theft warning siren (self power siren) can sound by its internal battery in case the vehicle battery cable is disconnected.

  • The main body ECU (instrument panel junction block assembly) sends an arming signal to the theft warning siren (self power siren) while switching 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 (instrument panel junction block assembly) can cause the theft warning siren (self power siren) to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

B159044E09

CAUTION / NOTICE / HINT

Note:

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

PROCEDURE

  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (THEFT WARNING SIREN [SELF POWER SIREN])

    1. Operate the intelligent tester according to the steps on the display and select "Active Test" (Click here).

      Table 1. Main Body

      Tester Display

      Test Part

      Control Range

      Diagnostic Note

      Security Horn2

      Theft warning siren (self power siren)

      ON/OFF

      -

      OK

      Siren operates normally.

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

  2. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN [SELF POWER SIREN] - BODY GROUND)

    1. U122343E02

      Disconnect the O15 siren connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      O15-2 (GND) - Body ground

      Always

      Below 1 Ω

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      O15-1 (+B) - Body ground

      Always

      11 to 14 V
    Table 2. Text in Illustration

    *1

    Front view of wire harness connector

    (to Theft Warning Siren [Self Power Siren])

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK THEFT WARNING SIREN (SELF POWER SIREN)

    1. Using an oscilloscope, check waveform 1.

      B229184E03
      Table 3. Measurement Condition

      Item

      Content

      Tester Connection

      O15-3 (CONT) - Body ground

      Tool Setting

      2 V/DIV., 20 msec./DIV.

      Condition

      Switched from armed state or arming preparation state to disarmed state

    2. Using an oscilloscope, check waveform 2.

      Table 4. Measurement Condition

      Item

      Content

      Tester Connection

      O15-3 (CONT) - Body ground

      Tool Setting

      2 V/DIV., 20 msec./DIV.

      Condition

      Switched from arming preparation state to armed state

    OK

    Waveform is output normally (refer to illustration).

    REPLACE THEFT WARNING SIREN (SELF POWER SIREN)

    (Click here)

  4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - THEFT WARNING SIREN [SELF POWER SIREN])

    1. U122537E02

      Disconnect the H80 ECU connector.

    2. Disconnect the O15 siren connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H80-6 (SSCL) - O15-3 (CONT)

      Always

      Below 1 Ω

      H80-6 (SSCL) or O15-3 (CONT) - Body ground

      Always

      10 kΩ or higher
      Table 5. Text in Illustration

      *1

      Front view of wire harness connector

      (to Main Body ECU [Instrument Panel Junction Block Assembly])

      *2

      Front view of wire harness connector

      (to Theft Warning Siren [Self Power Siren])

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    REPAIR OR REPLACE HARNESS OR CONNECTOR