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 assembly to sound at intervals of 0.4 seconds.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN)

   
   

   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.

      
      Body Electrical > Main Body > Active Test

      Tester Display	Measurement Item	Control Range	Diagnostic Note
      Security Horn	Security horn Assembly	OFF/ON	-

      
      Body Electrical > Main Body > Active Test

      Tester Display
      Security Horn

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

      Result
      Proceed to OK NG

   
   

   OK

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

   NG

2. INSPECT SECURITY HORN ASSEMBLY

   
   

   1. Remove the security horn assembly.

      Click here

   2. Inspect the security horn assembly.

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE SECURITY HORN ASSEMBLY Click here

   OK

3. INSPECT S-HORN_RLY/P RELAY

   
   
   1. 

      *1	S-HORN_RLY/P Relay

      Remove the S-HORN_RLY/P relay.

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

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

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE S-HORN_RLY/P RELAY

   OK

4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   

   1. Remove the main body ECU (multiplex network body ECU).

      Click here

      

      *a

      Component without harness connected (Instrument Panel Junction Block Assembly)

      -

      -

   2. Disconnect the 4C 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 4C-26 - MB-29 (SH) Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

   OK

5. CHECK HARNESS AND CONNECTOR (AUXILIARY BATTERY - S-HORN_RLY/P RELAY)

   
   

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

      Standard Voltage
      Tester Connection Condition Specified Condition Q66-1 - Body ground Power switch off 11 to 14 V Q66-5 - Body ground Power switch off 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. CHECK HARNESS AND CONNECTOR (S-HORN_RLY/P RELAY - SECURITY HORN ASSEMBLY)

   
   

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

      Standard Resistance
      Tester Connection Condition Specified Condition Q66-3 - A20-1 Always Below 1 Ω Q66-3 - Body ground Always 10 kΩ or higher A20-1 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. CHECK HARNESS AND CONNECTOR (S-HORN_RLY/P 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 Q66-2 - 4C-26 Always Below 1 Ω Q66-2 - Body ground Always 10 kΩ or higher 4C-26 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

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

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR