Theft Deterrent System Security Horn Circuit

Securities. Lexus Gs430, Gs300. Uzs190 Grs190
Theft Deterrent. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SECURITY HORN)

INSPECT SECURITY HORN ASSEMBLY

CHECK WIRE HARNESS (MULTIPLEX NETWORK BODY ECU - SECURITY HORN ASSEMBLY)

THEFT DETERRENT SYSTEM - Security Horn Circuit


DESCRIPTION

  1. When the theft deterrent system is operating, the multiplex network body ECU outputs a signal continuously at 0.4 second intervals, causing the security horn to sound.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Security Horn Circuit


INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SECURITY HORN)

  1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the security horn sounds.

    Multiplex network body ECU
    Item
    		Test Details
    		Diagnostic Note
    Security Horn
    		Security horn ON/OFF
    		-
    OK:
    Security horn operates normally.


NG
Go to step 2
OK

REPLACE COWL SIDE JUNCTION BLOCK RH (MULTIPLEX NETWORK BODY ECU)

2.INSPECT SECURITY HORN ASSEMBLY
Lexus Gs430, Gs300. Uzs190 Grs190

  1. Remove the security horn.

  1. Check operation of the horn.

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


NG
REPLACE SECURITY HORN ASSEMBLY
OK


3.CHECK WIRE HARNESS (MULTIPLEX NETWORK BODY ECU - SECURITY HORN ASSEMBLY)
Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Security Horn Circuit

  1. Disconnect the A41 ECU connector.

  1. Disconnect the A28 horn connector.

  1. Check the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    A41-1 (SH) - A28-1
    		Below 1 Ω
    A41-1 (SH) or A28-1 - Body sound
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE COWL SIDE JUNCTION BLOCK RH (MULTIPLEX NETWORK BODY ECU)