Theft Deterrent System Theft Warning Siren Circuit

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK THEFT WARNING SIREN

CHECK WIRE HARNESS (MULTIPLEX NETWORK BODY ECU - THEFT WARNING SIREN)

CHECK WIRE HARNESS (THEFT WARNING SIREN - BODY GROUND)

THEFT DETERRENT SYSTEM - Theft Warning Siren Circuit


DESCRIPTION

  1. The theft warning siren has an internal battery. If any of the vehicle's battery or communication line is opened, the theft warning siren detects it by itself and sounds. Although the theft warning siren usually sounds by receiving a signal from the multiplex network body ECU the theft warning siren can sound by its internal battery in case the vehicle's battery is opened.
  2. The multiplex network body ECU sends an arming signal to the theft warning siren while transferring to the armed state, and it also sends a disarming signal to the siren while switching to the disarmed state. Besides, the multiplex network body ECU can cause the theft warning siren to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Theft Warning Siren Circuit


INSPECTION PROCEDURE

1.CHECK THEFT WARNING SIREN


    Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Theft Warning Siren Circuit

  1. Measure the voltage of the connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    V37-1 (+B) - Body ground
    		Always
    		10 to 14 V
    V37-2 (GND) - Body ground
    		Always
    		Below 1 V
    V37-3 (CONT) - Body ground
    		When switched from armed state or arming preparation state to disarmed state (1)
    		Wave pattern (1) shown in chart below
    When switched from arming preparation state to armed state (2)
    		Wave pattern (2) shown in chart below
    Normal condition (Except (1) and (2))
    		Approx. 1.4 V


  1. Wave pattern


    Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Theft Warning Siren Circuit



NG
REPLACE THEFT WARNING SIREN
OK


2.CHECK WIRE HARNESS (MULTIPLEX NETWORK BODY ECU - THEFT WARNING SIREN)
Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Theft Warning Siren Circuit

  1. Disconnect the U8 ECU connector.

  1. Disconnect the V37 siren connector.

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    U8-12 (SSCL) - V37-3 (CONT)
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK WIRE HARNESS (THEFT WARNING SIREN - BODY GROUND)
Lexus Gs430, Gs300. Uzs190 Grs190.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Theft Warning Siren Circuit

  1. Disconnect the V37 siren connector.

  1. Check the resistance between the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    V37-2 (GND) - Body ground
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

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