THEFT DETERRENT SYSTEM Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) transmits a signal to cause the security horn to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

A01G4AWE13

INSPECTION PROCEDURE

Note


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

  • If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Perform the Active Test according to the display on the GTS.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Security Horn Security horn OFF/ON -
      OK
      The security horn assembly sounds and stops correctly when operated through the GTS.

    NG

    INSPECT SECURITY HORN ASSEMBLY Click here

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

  2. INSPECT SECURITY HORN ASSEMBLY


    1. A01G7JQ

      Remove the security horn assembly Click here.

    2. Check the operation of the security horn assembly.

      Standard
      Connection Specified Condition
      Battery positive (+) → Terminal 1 Horn sounds
      Battery negative (-) → Horn body

    NG

    REPLACE SECURITY HORN ASSEMBLY Click here

    OK

  3. INSPECT S-HORN RELAY


    1. A01G6BUE02
      Text in Illustration
      *a S-HORN Relay

      Remove the S-HORN relay from engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Condition Condition Specified Condition
      3 - 5 When battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage is applied between terminals 1 and 2 Below 1 Ω

    NG

    REPLACE S-HORN RELAY

    OK

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the main body ECU (multiplex network body ECU) Click here.

      A01G770E18
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -

    2. Disconnect the 3D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3D-14 - MB-17 (SH) Always Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (BATTERY - S-HORN RELAY)


    1. A01G8OJE03
      Text in Illustration
      *a Engine Room Relay Block and Junction Block Assembly

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Engine room relay block and junction block assembly S-HORN relay terminal 1- Body ground Always 11 to 14 V
      Engine room relay block and junction block assembly S-HORN relay terminal 5 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (S-HORN RELAY - SECURITY HORN ASSEMBLY)


    1. A01G8OJE03
      Text in Illustration
      *a Engine Room Relay Block and Junction Block Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Engine room relay block and junction block assembly S-HORN relay terminal 3 - A37-1 Always Below 1 Ω
      Engine room relay block and junction block assembly S-HORN relay terminal 3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (S-HORN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. A01G8OJE03
      Text in Illustration
      *a Engine Room Relay Block and Junction Block Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Engine room relay block and junction block assembly S-HORN relay terminal 2 - 3D-14 Always Below 1 Ω
      Engine room relay block and junction block assembly S-HORN relay terminal 2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here