Lexus IS250 IS220d GSE20 ALE20 - THEFT DETERRENT

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK THEFT WARNING SIREN ASSEMBLY

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - THEFT WARNING SIREN)

CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - COWL SIDE J/B RH - BATTERY)

CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - BODY GROUND)

THEFT DETERRENT SYSTEM (w/ Intrusion Sensor) - Theft Warning Siren Circuit

DESCRIPTION

The theft warning siren has an internal battery. If the vehicle's battery or any of the communication lines is open, the theft warning siren detects it by itself and sounds. Although the theft warning siren usually sounds by receiving a signal from the main body ECU RH, the theft warning siren can sound by its internal battery in case the vehicle's battery is open.
The main body ECU RH 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. Also, the main body ECU RH can cause the theft warning siren to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.CHECK THEFT WARNING SIREN ASSEMBLY
Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

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

  • Standard voltage:
  • Tester ConnectionConditionSpecified Condition
    P36-1 (+B) - Body groundAlways10 to 14 V
    P36-2 (GND) - Body groundAlwaysBelow 1 V
    P36-3 (CONT) - Body groundWhen switched from armed state or arming preparation state to disarmed state (1)Pulse generation*1
    (Using oscilloscope)
    When switched from arming preparation state to armed state (2)Pulse generation*2
    (Using oscilloscope)
    Normal condition (Except (1) and (2))Approx. 1.4 V

Wave pattern of the pulse generation *1 and *2

Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

NG
Go to step 2
OK
REPLACE THEFT WARNING SIREN ASSEMBLY
2.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - THEFT WARNING SIREN)
Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

Disconnect the J75 ECU and P36 siren connector.

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

  • Standard resistance:
  • Symbol (Tester Connection)Specified Condition
    SSCL (J75-12) - CONT (P36-3)Below 1 Ω
    SSCL (J75-12) - Body ground10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
3.CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - COWL SIDE J/B RH - BATTERY)
Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

Disconnect RJ and RK J/B connectors.

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

  • Standard:
  • Symbol (Tester Connection)Specified Condition
    +B (P36-1) - RJ-19Below 1 Ω
    +B (P36-1) - Body ground10 kΩ or higher
    RK-5 - Body ground10 to 14 v
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
4.CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN - BODY GROUND)
Theft Deterrent System (W/ Intrusion Sensor) - Theft Warning Siren Circuit. THEFT DETERRENT. Lexus IS250 IS220d GSE20 ALE20

Disconnect the P36 siren connector.

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

  • Standard resistance:
  • Symbol (Tester Connection)Specified Condition
    GND (P36-2) - Body groundBelow 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH)
LEXUS IS250, IS220d / GSE20 ALE20
THEFT DETERRENT
Lexus IS250 IS220d GSE20 ALE20
THEFT DETERRENT SYSTEM w/ Intrusion Sensor