Important Preliminary Checks Before Starting: Perform
Diagnostic System Check - Horns
before using the symptom tables in order to verify that all
of the following are true:
- There are no DTCs set.
- The body control module (BCM) can communicate via the serial data
link.
Review the system operation in order to familiarize yourself with the
system functions. Refer to
Horns Operation
.
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical
check. This step is extremely important-it could lead to correcting a problem
without further checks and can save valuable time. These checks include
the following:
| • | Inspect the easily accessible or visible system components and
harness connectors for obvious damage or conditions which could cause the
symptom. |
| • | Perform the following if the 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). |
Intermittents
Important: Faulty electrical connections or wiring may also 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 a symptom that does not set a DTC:
