THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DESCRIPTION

• The theft warning siren assembly has an internal battery. If the auxiliary battery or any of the communication lines are open, the theft warning siren assembly detects this and sounds its siren.

• Although the theft warning siren assembly usually sounds by receiving a signal from the main body ECU (multiplex network body ECU), the theft warning siren assembly can sound by its internal battery in case the auxiliary battery is open.

• The main body ECU (multiplex network body ECU) sends an arming signal to the theft warning siren assembly 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 (multiplex network body ECU) can cause the theft warning siren assembly 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. Connect the intelligent tester to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the intelligent tester on.

   4. Select the item below in the Active Test and then check that the theft warning siren operates.

   5. Operate the intelligent tester according to the steps on the display and select "Active Test".

      Main Body

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

      OK
      The theft warning siren assembly sounds and stops correctly when operated though the intelligent tester.

   
   

   NG

   INSPECT THEFT WARNING SIREN Click here

   OK

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

2. INSPECT THEFT WARNING SIREN

   
   

   1. 

      Remove the theft warning siren assembly with harness connected Click here.

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

      Standard Voltage

      Tester Connection Condition Specified Condition S21-1 (+B) - Body ground Always 11 to 14 V S21-2 (GND) - Body ground Always Below 1 V S21-3 (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

   3. Wave pattern

      

   
   

   NG

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

   OK

   REPLACE THEFT WARNING SIREN Click here

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

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU))
      *2	Front view of wire harness connector (to Theft Warning Siren Assembly)

      Disconnect the L8 main body ECU (multiplex network body ECU) and S21 theft warning siren assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition L8-18 (SSCL) - S21-3 (CONT) Always Below 1 Ω L8-18 (SSCL) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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

   

   Text in Illustration

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

   
   

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

      Standard Resistance
      Tester Connection Condition Specified Condition S21-2 (GND) - Body ground Always Below 1 Ω

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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