Horn System

WARNING: This page is about a different car, the 2000 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

Three different horns are used. One theft-deterrent horn mounted on passenger's strut tower. Two standard horns are mounted in front of radiator. Theft-deterrent horn is entirely controlled by theft-deterrent ECU. Standard horns are controlled either by pushing horn switch, or by body control ECU when theft-deterrent system has been activated. For diagnostic testing procedures covering theft-deterrent system horn operation, see TEST NO. 8: WHEN ALARM IS TRIGGERED, HORN DOES NOT SOUND under SYMPTOM TESTS in ANTI-THEFT SYSTEMS - AVALON article.

If standard horns are inoperative when horn switch is depressed, check horn switch for continuity to ground when depressed. Replace horn switch if no continuity exists. If horn switch is okay, check Green/Black wire between horn switch and horn relay. See WIRING DIAGRAMS in STEERING COLUMN SWITCHES - CARS article. Otherwise, testing procedures are the same as for theft-deterrent system standard horn malfunction.