THEFT DETERRENT SYSTEM (w/o Entry and Start System) Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (cowl side junction block assembly LH) transmits a signal to cause the security horn to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the intelligent tester on.

   4. Enter the following menus: Body / Main Body / Active Test.

   5. According to the display on the intelligent tester, perform the Active Test.

      Main 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 (COWL SIDE JUNCTION BLOCK ASSEMBLY LH)

2. INSPECT SECURITY HORN ASSEMBLY

   
   

   1. 

      Remove the security horn assembly Click here.

   2. Check the operation of the security horn assembly.

      Standard
      Measurement Condition Specified Condition Battery positive (+) → Terminal 1 Horn sounds Battery negative (-) → Horn body

   
   

   NG

   REPLACE SECURITY HORN ASSEMBLY Click here

   OK

3. INSPECT SECURITY HORN RELAY

   
   
   1. 

      Text in Illustration

      *a	SECURITY HORN Relay

      Remove the SECURITY HORN relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Specified Condition 3 - 5 10 kΩ or higher (when battery voltage is not applied between terminals 1 and 2) 3 - 5 Below 1 Ω (when battery voltage is applied between terminals 1 and 2)

   
   

   NG

   REPLACE SECURITY HORN RELAY

   OK

4. CHECK HARNESS AND CONNECTOR (BATTERY - SECURITY HORN RELAY)

   
   
   1. 

      Text in Illustration

      *a	Engine Room Relay Block
      *b	SECURITY HORN Relay

      Remove the SECURITY HORN relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition Engine room relay block and junction block assembly SECURITY HORN relay terminal 2- Body ground Always 11 to 14 V Engine room relay block and junction block assembly SECURITY HORN relay terminal 5 - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. CHECK HARNESS AND CONNECTOR (SECURITY HORN RELAY - SECURITY HORN ASSEMBLY)

   
   

   1. Remove the SECURITY HORN relay from the engine room relay block.

   2. Disconnect the A19 security horn assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Engine room relay block and junction block assembly SECURITY HORN relay terminal 3 - A19-1 Always Below 1 Ω Engine room relay block and junction block assembly SECURITY HORN relay terminal 3 - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. CHECK HARNESS AND CONNECTOR (SECURITY HORN RELAY - MAIN BODY ECU)

   
   

   1. Remove the SECURITY HORN relay from the engine room relay block.

   2. Disconnect the E4 main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Engine room relay block and junction block assembly SECURITY HORN relay terminal 2 - E4-6 (SH) Always Below 1 Ω Engine room relay block and junction block assembly SECURITY HORN relay terminal 2 - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK ASSEMBLY LH)