THEFT DETERRENT SYSTEM (w/o Intrusion Sensor) Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) controls the security horn.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

   
   

   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 security horn assembly operates.

      Body

      Tester Display	Test Part	Control Range	Diagnostic Note
      Security Horn	Security horn	ON/OFF	-

      OK
      The security horn assembly sounds and stops correctly when operated through the intelligent tester.

   
   

   NG

   INSPECT SECURITY HORN ASSEMBLY Click here

   OK

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

2. INSPECT SECURITY HORN ASSEMBLY

   
   

   1. 

      Remove the security horn assembly Click here.

   2. Check the operation of the security horn assembly.

      OK
      Battery Connection Specified Condition Battery positive (+) → A8-1 (B) Horn sounds Battery negative (-) → Horn body

   
   

   NG

   REPLACE SECURITY HORN ASSEMBLY Click here

   OK

3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   

   1. Disconnect the 2F instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors.

      

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

      Standard Resistance
      Tester Connection Condition Specified Condition 2F-22 - A-17 (SH) Always Below 1 Ω

      Text in Illustration

      *1

      Component without harness connected (Instrument Panel Junction Block Assembly)

      *2

      Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU))

   
   

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   OK

4. INSPECT POWER DISTRIBUTOR (S-HORN RELAY)

   
   
   1. 

      Text in Illustration

      *1	Component without harness connected (Engine Room Junction Block Assembly (Power Distributor))
      *2	Component without harness connected (Engine Room Junction Block Assembly (Power Distributor))

      Remove the power distributor from the engine room relay block Click here.

   2. Connect a positive (+) lead from the battery to terminal 3A-1.

   3. Connect a negative (-) lead from the battery to terminal 3C-8.

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

      Standard Voltage
      Tester Connection Condition Specified Condition 3C-9 - Battery negative (-) Always 11 to 14 V

   
   

   NG

   REPLACE POWER DISTRIBUTOR Click here

   OK

5. CHECK HARNESS AND CONNECTOR (S-HORN RELAY POWER SOURCE)

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector (to Engine Room Junction Block Assembly (Power Distributor))

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

      Standard Voltage
      Tester Connection Condition Specified Condition 3A-1 - Body ground Power switch off 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR (S-HORN RELAY) - MAIN BODY ECU)

   
   

   1. Reconnect the 2F instrument panel junction block assembly connector.

      

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3C-8 - A-17 (SH) Always Below 1 Ω 3C-8 - Body ground Always 10 kΩ or higher

      Text in Illustration

      *1

      Front view of wire harness connector (to Engine Room Junction Block Assembly (Power Distributor))

      *2

      Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU))

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. CHECK HARNESS AND CONNECTOR (SECURITY HORN ASSEMBLY - POWER DISTRIBUTOR (S-HORN RELAY))

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector (to Security Horn Assembly)
      *2	Front view of wire harness connector (to Engine Room Junction Block Assembly (Power Distributor))

      Disconnect the A8 security horn assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A8-1 (B) - 3C-9 Always Below 1 Ω 3C-9 - 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