Security Horn Circuit: Procedure

1. Disconnect the D10 ECU connector.
   Fig 1: Identifying D10 ECU Connector Terminal 6 (SH)

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2. Connect a negative battery lead to terminal 6 (SH) of the D10 ECU connector.
3. Check operation of the security horn.

   OK

   Measurement Condition	Specified Condition
   Battery negative (-) → D10-6 (SH)	Horn sounds

NG → See step   2 

OK → See step   6 

1. Remove the security horn assembly, refer to REMOVAL .
   Fig 2: Checking Operation Of Horn

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2. Check operation of the horn.

   OK

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

NG → See step   7 

OK: Go to next step 

1. Disconnect the 2A engine room junction block assembly connector and A15 security horn assembly connector.
   Fig 3: Identifying 2A Engine Room Junction Block Assembly Connector & A15 Security Horn Assembly Connector

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

   Standard resistance

   Tester Connection	Condition	Specified Condition
   2A-9 - A15-1	Always	Below 1 Ω
   2A-9 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the 2D engine room junction block assembly connector.
   Fig 4: Identifying 2D Engine Room Junction Block Assembly Connector

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2. Measure the voltage on the relay block side according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   2D-1 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the 2A engine room junction block assembly connector.
2. Disconnect the D10 ECU connector.
3. Measure the resistance according to the value(s) in the table below.
   Fig 5: Identifying 2A Engine Room Junction Block Assembly Connector & D10 ECU Connector

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   Standard resistance

   Tester Connection	Condition	Specified Condition
   2A-6 - D10-6 (SH)	Always	Below 1 Ω
   D10-6 (SH) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY