Inspection Procedure

1. Connect the battery's positive (+) lead to the terminal, and the negative (-) lead to the horn body.
2. Check that the horn sounds.

   Standard: 

   Horn sounds 

NG: REPLACE LOW PITCHED HORN ASSEMBLY 

Fig 1: Inspecting Low Pitched Horn Assembly

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OK : Go to Next Step 

1. Remove the HORN relay from the engine room R/B.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG: REPLACE HORN RELAY 

Fig 2: Identifying Relay

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OK : Go to Next Step 

1. Remove the HORN relay from the engine room R/B.
2. Disconnect the T3 TVIP ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   HORN (T3-5) - R/B HORN relay terminal 2	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

Fig 3: Identifying TVIP ECU Connector And HORN Relay Terminal

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OK : Go to Next Step 

1. Remove the HORN relay from the engine room R/B.
2. Disconnect the HORN connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   R/B HORN relay terminal 3 - HORN (H6-1)	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

Fig 4: Identifying HORN Relay Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE TVIP ECU