Horn Circuit [10/2014 - ]: Procedure

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

   Result

   Result	Proceed to
   Horns sound	A
   Horns do not sound	B

Result: 

B 

GO TO HORN SYSTEM 

(Refer to PROBLEM SYMPTOMS TABLE [10/2014 - ] )

Result: 

A 

See step  2

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-15 - MB-28 (HORN)	Always	Below 1 Ω

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

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

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

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