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 assembly to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

A002AE2E11

CAUTION / NOTICE / HINT

Note


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

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


    • *: w/ Smart Entry and Start System

  • As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure.*

    Click here


    • *: for LHD

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    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.


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Security Horn Security horn assembly OFF/ON -

      Body Electrical > Main Body > Active Test
      Tester Display
      Security Horn
      OK
      The security horn 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. INSPECT SECURITY HORN ASSEMBLY


    1. Remove the security horn assembly.

      Click here

    2. Inspect the security horn assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SECURITY HORN ASSEMBLY Click here

    OK

  3. INSPECT S-HORN RELAY


    1. A002B4NC02
      *1 S-HORN Relay

      Remove the S-HORN relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    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

      B003ZFOC02
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -

    2. Disconnect the 4F 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
      4F-31 - MB-29 (SH) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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


    1. A002ASDC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 1 - Body ground Always 11 to 14 V
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A002ASDC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 3 - A36-1 Always Below 1 Ω
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 3 or A36-1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A002ASDC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 2 - 4F-31 Always Below 1 Ω
      No. 1 engine room relay block and No. 1 junction block assembly S-HORN relay terminal 2 or 4F-31 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR