Security Horn Circuit [10/2014 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Perform the Active Test according to the display on the Techstream.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Security Horn	Security horn	OFF/ON	-

   OK

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

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )

Result: 

NG 

See step  2

1. Remove the security horn assembly (Refer to REMOVAL [10/2014 - ] ).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Check the operation of the security horn assembly.

   OK

   Auxiliary Battery Connection	Specified Condition
   Auxiliary battery positive (+) → Terminal 1	Horn sounds
   Auxiliary battery negative (-) → Horn body

Result: 

NG 

REPLACE SECURITY HORN ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

OK 

See step  3

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	When auxiliary battery voltage is not applied between terminals 1 and 2	10 kΩ or higher
   3 - 5	When auxiliary battery voltage is applied between terminals 1 and 2	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	S-HORN Relay

Result: 

NG 

REPLACE S-HORN RELAY 

Result: 

OK 

See step  4

1. Remove the main body ECU (multiplex network body ECU) (Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] ).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   -

   -

2. Disconnect the 3D 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
   3D-14 - MB-17 (SH)	Always	Below 1 Ω

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )

Result: 

OK 

See step  5

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Engine room relay block and junction block assembly S-HORN relay terminal 1- Body ground	Power switch off	11 to 14 V
   Engine room relay block and junction block assembly S-HORN relay terminal 3 - Body ground	Power switch off	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Engine Room Relay Block and Junction Block Assembly

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Engine room relay block and junction block assembly S-HORN relay terminal 5 - K25-1	Always	Below 1 Ω
   Engine room relay block and junction block assembly S-HORN relay terminal 5 - Body ground	Always	10 kΩ or higher
   K25-1 - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Engine Room Relay Block and Junction Block Assembly

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  7

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Engine room relay block and junction block assembly S-HORN relay terminal 2 - 3D-14	Always	Below 1 Ω
   Engine room relay block and junction block assembly S-HORN relay terminal 2 - Body ground	Always	10 kΩ or higher
   3D-14 - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Engine Room Relay Block and Junction Block Assembly

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR