THEFT DETERRENT SYSTEM Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the body ECU transmits a signal to cause the security horn to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

B00270IE03

CAUTION / NOTICE / HINT

Note


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

  • w/ Door Control Battery:

    As the door control battery is installed between the vehicle battery and body ECU, first perform the inspections to confirm that there are no malfunctions in the power source circuit for the body ECU before performing this troubleshooting procedure.

    Click here

  • w/ Automatic Light Control System:

    If the body ECU has been replaced, it is necessary to initialize the body ECU.

    Click here

PROCEDURE


  1. 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

  2. INSPECT HORN RELAY (S-HORN)


    1. B0028SPC05
      *1 Horn Relay (S-HORN)

      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 Battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage is applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HORN RELAY (S-HORN)

    OK

  3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the body ECU.


    2. Disconnect the instrument panel junction block assembly connector.

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

      B00284RC15
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      2P-14 - A-10 (SH) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG (for LHD)
      NG (for RHD)

    NG (for LHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG (for RHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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


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

    2. B0027Y7

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 1 - Body ground Always 11 to 14 V
      Relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

    2. Disconnect the A42 security horn assembly connector.

    3. Disconnect the 2P instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 3 - A42-1 Always Below 1 Ω
      Relay terminal 2 - 2P-14 Always Below 1 Ω
      Relay terminal 3 - Body ground Always 10 kΩ or higher
      Relay terminal 2 - Body ground Always 10 kΩ or higher
      A42-1 - Body ground Always 10 kΩ or higher
      2P-14 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK (for LHD)
      OK (for RHD)
      NG

    OK (for LHD)

    REPLACE BODY ECU Click here

    OK (for RHD)

    REPLACE BODY ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR