THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DESCRIPTION

• The theft warning siren assembly (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 assembly (self power siren) detects this and sounds its siren.

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

• The main body ECU sends an arming signal to the theft warning siren assembly (self power siren) while switching to the armed state, and it sends a disarming signal to the siren while switching to the disarmed state. Also, the main body ECU can cause the theft warning siren assembly (self power siren) to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (THEFT WARNING 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.

   
   

   NG

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

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

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

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to Theft Warning Siren Assembly)

      Disconnect the Q33 siren connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Q33-2 (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 Q33-5 (+B) - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. CHECK MAIN BODY ECU (OUTPUT SIGNAL)

   
   

   1. Using an oscilloscope, check waveform 1.

      

      Text in Illustration

      *a	Component with harness connected (Main Body ECU)	*b	Waveform 1
      *c	Waveform 2	-	-

      Measurement Condition

      Item	Content
      Tester Connection	G63-18 (SSCL) - Body ground
      Tool Setting	2 V/DIV., 20 ms./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	G63-18 (SSCL) - Body ground
      Tool Setting	2 V/DIV., 20 ms./DIV.
      Condition	Switched from arming preparation state to armed state

      OK
      Waveform is output normally (refer to illustration).

   
   

   NG

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

   OK

   REPLACE THEFT WARNING SIREN ASSEMBLY (SELF POWER SIREN) Click here

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

   
   

   1. Disconnect the Q33 siren connector.

   2. Disconnect the G63 ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Q33-4 (CONT) - G63-18 (SSCL) Always Below 1 Ω Q33-4 (CONT) or G63-18 (SSCL) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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