Theft Deterrent / Keyless Entry

Horn Circuit

~1min read
DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (driver side junction block assembly) transmits a signal to cause the horn to sound at intervals of 0.4 seconds.

WIRING DIAGRAM
PROCEDURE
  1. INSPECT HORNS

(a) Press the horn switch and check if the horns sound.

Result

Proceed to

Horns sound

A

Horns do not sound

B


B

GO TO HORN SYSTEM

A
  1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Select the item below in the Active Test and then check that the horns operate.

Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Vehicle Horn

Vehicle horns

ON / OFF

-

OK:

The vehicle horns sound and stop correctly when operated through the Techstream.


OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE


NG

REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

Test yourself

A quick Toyota Venza quiz: every answer comes with an explanation and a link to the manual page.