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

A01HHDKE04

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 the Service Bulletin.

  • 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.*

    *: w/ Door Control Battery

    Click here

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN)


    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. According to the display on the GTS, perform the Active Test.


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

      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 (for LHD)
      OK (for RHD)
      NG

    OK (for LHD)

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

    OK (for RHD)

    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 SECURITY WARNING RELAY (S-HORN RELAY)


    1. A01HEO3E01

      Remove the security warning relay (S-HORN relay).

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

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

    NG

    REPLACE SECURITY WARNING RELAY (S-HORN RELAY)

    OK

  4. CHECK HARNESS AND CONNECTOR (SECURITY WARNING RELAY [S-HORN RELAY] - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


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


    2. Connect the instrument panel junction block assembly connectors.

    3. Remove the security warning relay (S-HORN relay).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 - A-29 (SH) Always Below 1 Ω
      2 - Body ground Always 10 kΩ or higher
      A-29 (SH) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (SECURITY HORN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (BATTERY - SECURITY WARNING RELAY [S-HORN RELAY])


    1. A01HIWS

      Remove the security warning relay (S-HORN relay).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 - Body ground Always 11 to 14 V
      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 (SECURITY WARNING RELAY [S-HORN RELAY] - SECURITY HORN ASSEMBLY AND BODY GROUND)


    1. Remove the security warning relay (S-HORN relay).

    2. Disconnect the A10 security horn assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - A10-1 Always Below 1 Ω
      A10-2 - Body ground Always Below 1 Ω
      3 - Body ground Always 10 kΩ or higher
      A10-1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK (for LHD)
      OK (for RHD)
      NG

    OK (for LHD)

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

    OK (for RHD)

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. Disconnect the 4B instrument panel junction block assembly connector.

    2. Remove the security warning relay (S-HORN relay).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 - 4B-48 Always Below 1 Ω
      2 - Body ground Always 10 kΩ or higher
      4B-48 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK (for LHD)
      OK (for RHD)
      NG

    OK (for LHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK (for RHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR