Important: The following steps must be completed before using the symptom tables.
- Perform
Diagnostic System Check - Vehicle
, before using the symptom tables in order to verify that all of the following are true:
| • | 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 System Description and Operation
.
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical inspection. 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. |
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
| • | Perform the following if the horns buzz or have a harsh tone: |
| - | Inspect for debris in the joints where the horns fasten 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
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections
.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose a symptom that does not set a DTC:
