How to Use The Diagnostic Procedure

Noise, vibration and harshness concerns have become more important as vehicles have become more sensitive to these conditions. This section is designed to aid in Identifying these situations and to provide diagnostic procedures based on symptoms. if the condition occurs at high speed, for instance, the most likely place to start is under High Speed Shake.
- The road test procedure will tell how to sort out the conditions into categories and how to tell a vibration from a shake.
- A series of Road Test Quick Checks is provided to make sure that a cause is either pinpointed or eliminated.
- Use the Vehicle Road Test Evaluation form to record road test results.
- Use the Glossary to become familiar with the terms.
- Name the condition, go to the appropriate section and locate the proper diagnosis. When the condition is identified, the job is partly done.
- Follow the diagnostic procedure.
- Follow the steps.
- Quick Checks are described within the step, while more involved tests and adjustments are found in Service Procedures and Adjustments.
- Always follow each step exactly and make notes to recall important findings.

Customer Interview
The road test and customer interview (If available) provide information that will help identify the concern and will provide direction to the correct starting point for diagnosis

Use the Customer Concern Evaluation form to record customer concerns.