Inspection and Verification (Start Testing Here)

This provides a working knowledge of the process of diagnosing Noise,Vibration and Harshness (NVH) Conditions. The Topics are based on the description of the condition. For example, if the condition is a shake that occurs at high speed, the most likely place to start is under High-Speed Shake in the symptom chart. The road test procedure will help you to sort the conditions into categories and distinguish a vibration from a shake. It also provides quick checks to help pinpoint or eliminate a cause.

How to Use the Diagnostic Procedure
Begin with the customer interview. Use the Glossary of Terms to find the descriptive name of conditions not encountered before. After naming it, identify the condition by performing a road test. Then, locate the proper diagnosis. Remember, by beginning at that point, most other systems in the vehicle have been eliminated; when the proper method of diagnosis is identified, the job is partly done. Follow the steps within the diagnostic procedure. Quick checks are described within the steps, while more involved procedures and adjustments are found in the General Procedures. Always follow each step exactly and make notes along the way to recall important findings later.