Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the multiplex network body ECU turns on the HORN relay, causing the horns to sound.

WIRING DIAGRAM

INSPECTION PROCEDURE

1. INSPECT HORN OPERATION

1. Press the horn switch and check if the horns sound.

   Result: 

   Result	Go to
   Horns sound	A
   Horns do not sound	B

B	GO TO HORN SYSTEM

A

2. READ DATA LIST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON.

3. Turn the intelligent tester main switch on.

4. Select the item below in the DATA LIST and read the display on the tester.

   BODY (Multiplex network body ECU): 

   Item	Test Details	Diagnostic Note
   Warning by Horn	Warning by horn ON/OFF	-

   Result: 

   Result	Go to
   OFF	Buzzer operation is set to off by customization.
   ON	A

A

3. PERFORM ACTIVE TEST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON.

3. Turn the intelligent tester main switch on.

4. Select the item below in the ACTIVE TEST and then check that the horns operate.

   BODY (Multiplex network body ECU): 

   Item	Test Details	Diagnostic Note
   Vehicle Horn	Vehicle horn ON/OFF	-

   OK:

   The vehicle horns sound or stop correctly when operating it through the intelligent tester.
   

NG	Go to step 4

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

4. CHECK HARNESS AND CONNECTOR (J/B NO.2 - INSTRUMENT PANEL J/B ASSEMBLY)

1. Disconnect the 2H J/B No.2 connector and 1D instrument panel J/B connector.
   

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

   Resistance:

   Tester Connection	Specified Condition
   2H-9 - 1D-11	Below 1 Ω
   2H-9 or 1D-11 - Body ground	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE INSTRUMENT PANEL J/B ASSEMBLY