Home

Toyota Workshop

GSIC - Global Service Information Center

THEFT DETERRENT SYSTEM > Security Horn Circuit

for Preparation Click here


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


B229045E01


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

  1. 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
Go to step 2
OK

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

2.INSPECT SECURITY HORN ASSEMBLY


    B229080

  1. Remove the security horn assembly (Click here).

  1. Check the operation of the security horn assembly.

    OK:
    Battery Connection
    		Specified Condition
    Battery positive (+) → A65-1
    		Horn sounds
    Battery negative (-) → Horn body



NG
REPLACE SECURITY HORN ASSEMBLY (Click here)
OK


3.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


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


    B220554E04

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2C-39 - 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 S-HORN RELAY


    B212810

  1. Remove the S-HORN relay from the engine room relay block.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3 - 5
    		Battery voltage supplied between terminals 1 and 2
    		Below 1 Ω
    3 - 5
    		Battery voltage not supplied between terminals 1 and 2
    		10 kΩ or higher



NG
REPLACE S-HORN RELAY
OK


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


    B229085E01

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    1 - Body ground
    		Always
    		11 to 14 V
    5 - Body ground
    		Always
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Engine Room Relay Block (S-HORN Relay))



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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


    B229086E01

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2 - 2C-39
    		Always
    		Below 1 Ω
    2C-39 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Engine Room Relay Block (S-HORN Relay))
    *2
    		Front view of wire harness connector
    (to Instrument Panel Junction Block Assembly)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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


    B229087E01

  1. Disconnect the A65 security horn assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A65-1 - 3
    		Always
    		Below 1 Ω
    A65-1 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Security Horn Assembly)
    *2
    		Front view of wire harness connector
    (to Engine Room Relay Block (S-HORN Relay))



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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