How To Use This Diagnostic Procedure

Noise, vibration and harshness (NVH) concerns have become more important as vehicles have become more sensitive to these vibrations. This article is designed to aid in identifying these concerns.
This article provides diagnostic procedures based on symptom. If the condition occurs at high speed, for instance, the most likely place to start is under Shake and Vibration While Driving.
The road test procedure will tell how to sort 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.
Identify the condition, proceed to the appropriate article and locate the correct diagnosis. When the condition is identified, the job is partly done.
Follow the diagnostic procedure as outlined.
Quick Checks are described within the step, while more involved tests and adjustments are outlined in General Procedures.
Always follow each step exactly and make notes to recall important findings later.