THEFT DETERRENT SYSTEM(w/o Entry and Start 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

A01X703E10

CAUTION / NOTICE / HINT

Note


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

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

  • *: w/ Door Control Battery

    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.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch ON.

    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.

      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.
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

  2. INSPECT SECURITY HORN ASSEMBLY


    1. Remove the security horn assembly Click here.

    2. Inspect the security horn assembly Click here.


    NG

    REPLACE SECURITY HORN ASSEMBLY Click here

    OK

  3. INSPECT HORN RELAY (S-HORN)


    1. A01X83RE03

      Remove the horn relay (S-HORN).

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

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

    NG

    REPLACE HORN RELAY [S-HORN]

    OK

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


    1. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH.


    2. Connect the cowl side junction block LH connectors.

    3. Remove the horn relay (S-HORN).

    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

    NG

    CHECK HARNESS AND CONNECTOR (HORN RELAY [S-HORN] - COWL SIDE JUNCTION BLOCK LH) Click here

    OK

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

    A01X6WP

    1. Remove the horn relay (S-HORN).

    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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (HORN RELAY [S-HORN] - SECURITY HORN ASSEMBLY AND BODY GROUND)


    1. Remove the horn relay (S-HORN).

    2. Disconnect the A53 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 - A53-1 Always Below 1 Ω
      3 - Body ground Always 10 kΩ or higher
      A53-1 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK HARNESS AND CONNECTOR (HORN RELAY [S-HORN] - COWL SIDE JUNCTION BLOCK LH)


    1. Disconnect the 2H cowl side junction block LH connector.

    2. Remove the horn relay (S-HORN).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 - 2H-26 Always Below 1 Ω
      2 - Body ground Always 10 kΩ or higher
      2H-26 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    B

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR