THEFT DETERRENT 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 (multiplex network body ECU) transmits a signal to cause the security horn to sound at intervals of 0.4 seconds.

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   PERFORM ACTIVE TEST USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

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

   5. Perform the Active Test according to the display on the GTS.

      Table 1. Main Body

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

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

   
   
   • OK

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

   • NGClick here
2. Click here

   INSPECT SECURITY HORN ASSEMBLY

   
   
   1. 

      Remove the security horn assembly (Click here).

   2. Check the operation of the security horn assembly.

      Standard
      Connection Specified Condition Auxiliary battery positive (+) → Terminal 1 Horn sounds Auxiliary battery negative (-) → Horn body

   
   
   • OKClick here
   • NG

     REPLACE SECURITY HORN ASSEMBLY (Click here)

3. Click here

   INSPECT S-HORN RELAY

   
   
   1. 

      Remove the S-HORN relay from engine room relay block and junction block assembly.

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

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

      Table 2. Text in Illustration

      *a	S-HORN Relay

   
   
   • OKClick here
   • NG

     REPLACE S-HORN RELAY

4. Click here

   INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   
   1. 

      Remove the main body ECU (multiplex network body ECU) (Click here).

      Table 3. Text in Illustration

      *a

      Component without harness connected (Instrument Panel Junction Block Assembly)

      -

      -

   2. Disconnect the 3D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3D-14 - MB-17 (SH) Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (Click here)

5. Click here

   CHECK HARNESS AND CONNECTOR (AUXILIARY BATTERY - S-HORN RELAY)

   
   
   1. 

      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 S-HORN relay terminal 1- Body ground Power switch off 11 to 14 V Engine room relay block and junction block assembly S-HORN relay terminal 5 - Body ground Power switch off 11 to 14 V

      Table 4. Text in Illustration

      *a	Engine Room Relay Block and Junction Block Assembly

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

6. Click here

   CHECK HARNESS AND CONNECTOR (S-HORN RELAY - SECURITY HORN ASSEMBLY)

   
   
   1. 

      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 S-HORN relay terminal 3 - Q19-1 Always Below 1 Ω Engine room relay block and junction block assembly S-HORN relay terminal 3 - Body ground Always 10 kΩ or higher

      Table 5. Text in Illustration

      *a	Engine Room Relay Block and Junction Block Assembly

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

7. Click here

   CHECK HARNESS AND CONNECTOR (S-HORN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   
   
   1. 

      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 S-HORN relay terminal 2 - 3D-14 Always Below 1 Ω Engine room relay block and junction block assembly S-HORN relay terminal 2 - Body ground Always 10 kΩ or higher

      Table 6. Text in Illustration

      *a	Engine Room Relay Block and Junction Block Assembly

   
   
   • OK

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

   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR