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

A01FUCHE04

INSPECTION PROCEDURE

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.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN)


    1. Connect the GTS to the DLC3.

    2. Turn the power 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.

      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 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. A01FSQB

      Remove the security horn assembly Click here.

    2. Check the operation of the security horn assembly.

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

    NG

    REPLACE SECURITY HORN ASSEMBLY Click here

    OK

  3. INSPECT NO. 1 JUNCTION BLOCK ASSEMBLY (SECURITY HORN RELAY)


    1. A01FTRPE01

      Disconnect the No. 1 junction block assembly (security horn relay) connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      6E-1 - 6A-15 When battery voltage is applied between terminals 6E-1 - 6B-9 Below 1 Ω
      6A-9 - 6A-15 10 kΩ or higher
      6E-1 - 6A-15 When battery voltage is not applied between terminals 6E-1 - 6B-9 10 kΩ or higher
      6A-9 - 6A-15 Below 1 Ω

    NG

    REPLACE NO. 1 JUNCTION BLOCK ASSEMBLY (SECURITY HORN RELAY)

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 1 JUNCTION BLOCK ASSEMBLY [SECURITY HORN RELAY] - MAIN BODY ECU)


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

    2. Connect the cowl side junction block LH connectors.

    3. Disconnect the 6B No. 1 junction block assembly (security horn relay) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      6B-9 - A-17 (SH) Always Below 1 Ω
      6B-9 - Body ground Always 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 JUNCTION BLOCK ASSEMBLY [SECURITY HORN RELAY] - COWL SIDE JUNCTION BLOCK LH) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (AUXILIARY BATTERY - NO. 1 JUNCTION BLOCK ASSEMBLY [SECURITY HORN RELAY])


    1. A01FV5EE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 Junction Block Assembly)

      Disconnect the No. 1 junction block assembly (security horn relay) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      6E-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 1 JUNCTION BLOCK ASSEMBLY [SECURITY HORN RELAY] - SECURITY HORN ASSEMBLY AND BODY GROUND)


    1. Disconnect the 6A No. 1 junction block assembly (security horn relay) connectors.

    2. Disconnect the A43 security horn assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      6A-15 - A43-1 Always Below 1 Ω
      6A-9 - Body ground Always Below 1 Ω
      6A-15 - 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

  7. CHECK HARNESS AND CONNECTOR (NO. 1 JUNCTION BLOCK ASSEMBLY [SECURITY HORN RELAY] - COWL SIDE JUNCTION BLOCK LH)


    1. Disconnect the 5A cowl side junction block LH connector.

    2. Disconnect the 6B No. 1 junction block assembly (security horn relay) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      6B-9 - 5A-46 Always Below 1 Ω
      6B-9 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here