THEFT DETERRENT SYSTEM 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 horns to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

B003ZBTE28

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. INSPECT HORNS


    1. Press the horn switch and check that the horns sound.

      Result
      Result Proceed to
      Horns sound A
      Horns do not sound B

    B

    GO TO HORN SYSTEM Click here

    A

  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


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

      Click here

      B003ZFOC01
      *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-29 - MB-28 (HORN) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here