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

A011Y07E03

INSPECTION PROCEDURE

Note

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

PROCEDURE

  1. PERFORM ACTIVE TEST USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

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

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

      Main Body (Main Body ECU (Multiplex Network Body ECU))
      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 Techstream.
    NG

    INSPECT SECURITY HORN ASSEMBLY Click here

    OK

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

  2. INSPECT SECURITY HORN ASSEMBLY

    1. Remove the security horn assembly Click here.

      A011YI3

    2. Check the operation of the security horn assembly.

      OK
      Measurement Condition Specified Condition
      Auxiliary battery positive (+) → Terminal 1 Horn sounds
      Auxiliary battery negative (-) → Horn body
    NG

    REPLACE SECURITY HORN ASSEMBLY Click here

    OK

  3. INSPECT S-HORN RELAY

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

      A011WNIE02

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 When auxiliary battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 When auxiliary battery voltage is applied between terminals 1 and 2 Below 1 Ω
      Text in Illustration
      *a S-HORN Relay
    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.

      A011W9NE16
      Text in Illustration
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -

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

    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 (AUXILIARY BATTERY - S-HORN RELAY)

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

      A011XRFE01
      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
      Text in Illustration
      *a Engine room relay block and junction block assembly
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

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

      A011XRFE01
      Standard Resistance
      Tester Connection Condition Specified Condition
      Engine room relay block and junction block assembly S-HORN relay terminal 3 - O27-1 Always Below 1 Ω
      Engine room relay block and junction block assembly S-HORN relay terminal 3 - Body ground Always 10 kΩ or higher
      Text in Illustration
      *a Engine room relay block and junction block assembly
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

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

      A011XRFE01
      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
      Text in Illustration
      *a Engine room relay block and junction block assembly
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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