THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DESCRIPTION

The theft warning siren has an internal battery. If the vehicle 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 certification ECU (smart key ECU assembly), the theft warning siren can sound by its internal battery in case the vehicle battery cable is disconnected.

The certification ECU (smart key ECU assembly) 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 certification ECU (smart key ECU assembly) can cause the theft warning siren to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

A01ENZEE04

INSPECTION PROCEDURE

Note


  • If the certification ECU (smart key ECU assembly) is replaced, refer to the Service Bulletin.

  • When replacing the theft warning siren assembly, refer to the Service Bulletin.

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SEQURITY HORN2)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Entry&Start / Active Test.

    5. According to the display on the intelligent tester, perform the Active Test.

      Entry&Start (Certification ECU [Smart Key ECU Assembly])
      Tester Display Test Part Control Range Diagnostic Note
      Security Horn2 Theft warning siren ON / OFF -
      OK
      The theft warning siren assembly sounds and stops correctly when operated through the intelligent tester.

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - BATTERY AND BODY GROUND)


    1. A01EPE0E05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Theft Warning Siren Assembly)

      Disconnect the K46 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
      K46-5 (+B) - Body ground Always 11 to 14 V
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      K46-2 (GND) - Body ground Always Below 1 Ω

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - CERTIFICATION ECU [SMART KEY ECU ASSEMBLY])


    1. Disconnect the K46 theft warning siren assembly connector.

    2. Disconnect the E30 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K46-4 (CONT) - E30-7 (SSCL) Always Below 1 Ω
      K46-4 (CONT) - Body ground Always 10 kΩ or higher

    NG
    OK
  4. CHECK THEFT WARNING SIREN ASSEMBLY


    1. Temporarily replace the theft warning siren assembly with a new or known good one (refer to the Service Bulletin).

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

      OK
      Theft warning siren assembly function operates normally.

    NG
    OK