Important: The following steps must be completed before
using the symptom tables:
- Perform the 
Diagnostic System Check - Vehicle 
 in Vehicle DTC Information, before
using the symptom tables in order to verify that all of the following are true:
 
| •  | The control modules can communicate via the serial data link. | 
 
- Review the system operation in order to familiarize yourself with the
system functions. Refer to 
Horns System Description and Operation 
.
 
Visual/Physical Inspection
|     •  | Inspect the easily accessible or visible system components for obvious
damage or conditions which could cause the symptom. | 
 
|     •  | Perform the following if a horn buzzes or has a harsh tone: | 
 
|        -  | Inspect for debris in the joint where the horn fastens to the vehicle. | 
 
|        -  | Test the torque of the horn mounting hardware. The horn mounting hardware
should be tightened to a torque of 10 N·m (7 lb ft). | 
 
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions.
Refer to 
Testing for Intermittent Conditions and Poor Connections 
 in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom: