THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DESCRIPTION

• The theft warning siren (self power siren) has an internal battery. If the vehicle battery cable is disconnected or any of the communication lines are open, the theft warning siren (self power siren) detects this and sounds its siren.

• Although the theft warning siren (self power siren) usually sounds by receiving a signal from the main body ECU (instrument panel junction block assembly), the theft warning siren (self power siren) can sound by its internal battery in case the vehicle battery cable is disconnected.

• The main body ECU (instrument panel junction block assembly) sends an arming signal to the theft warning siren (self power siren) while switching 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 (instrument panel junction block assembly) can cause the theft warning siren (self power siren) to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

*a	from Battery
*b	CONT
*c	Theft Warning Siren (Self Power Siren)
*d	Main Body ECU (Instrument Panel Junction Block Assembly)

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (THEFT WARNING SIREN [SELF POWER SIREN])

   
   

   1. Operate the intelligent tester according to the steps on the display and select "Active Test" Click here.

      Main Body

      Tester Display	Test Part	Control Range	Diagnostic Note
      Security Horn2	Theft warning siren (self power siren)	ON/OFF	-

      OK
      Siren operates normally.

   
   

   OK

   REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   NG

2. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN [SELF POWER SIREN] - BODY GROUND)

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector (to Theft Warning Siren [Self Power Siren])

      Disconnect the O15 siren connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition O15-2 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition O15-1 (+B) - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. CHECK THEFT WARNING SIREN (SELF POWER SIREN)

   
   

   1. Using an oscilloscope, check waveform 1.

      

      *1	Component with harness connected: (Theft Warning Siren [Self Power Siren])
      *2	CONT
      *3	Waveform 1
      *4	Waveform 2

      Measurement Condition

      Item	Content
      Tester Connection	O15-3 (CONT) - Body ground
      Tool Setting	2 V/DIV., 20 msec./DIV.
      Condition	Switched from armed state or arming preparation state to disarmed state

   2. Using an oscilloscope, check waveform 2.

      Measurement Condition

      Item	Content
      Tester Connection	O15-3 (CONT) - Body ground
      Tool Setting	2 V/DIV., 20 msec./DIV.
      Condition	Switched from arming preparation state to armed state

      OK
      Waveform is output normally (refer to illustration).

   
   

   OK

   REPLACE THEFT WARNING SIREN (SELF POWER SIREN) Click here

   NG

4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - THEFT WARNING SIREN [SELF POWER SIREN])

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector (to Main Body ECU [Instrument Panel Junction Block Assembly])
      *2	Front view of wire harness connector (to Theft Warning Siren [Self Power Siren])

      Disconnect the H80 ECU connector.

   2. Disconnect the O15 siren connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition H80-6 (SSCL) - O15-3 (CONT) Always Below 1 Ω H80-6 (SSCL) or O15-3 (CONT) - Body ground Always 10 kΩ or higher

   
   

   OK

   REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR