Important: The following steps must be completed before using the analysis tables or the symptom tables.

1. Perform the Vibration Analysis - Road Testing before using the other Vibration Analysis tables or the Symptom tables in order to effectively diagnose the customer's concern.

Using Vibration Analysis - Road Testing will first provide duplication of virtually any vibration concern and then identify the correct procedure for diagnosing the area of concern which has been duplicated.

2. Review the following Vibration Diagnostic Procedure.
3. Review the general descriptions to familiarize yourself with vibration theory and terminology, the J 38792-A Electronic Vibration Analyzer (EVA) 2 and the J 38792-VS Vibrate Software. Reviewing this kind of information will help you determine whether the condition described by the customer is a potential operating characteristic or not.

Refer to the following:

•	Vibration Theory and Terminology

•	Electronic Vibration Analyzer (EVA) Description and Operation

•	Drive Software Description and Operation

•	Reed Tachometer Description

Important: Using the following steps of the vibration diagnostic process will help you to effectively narrow-down and pin-point the search for the specific source of a vibration concern and to achieve accurate repair.

1. Gather specific information on the customer's vibration concern.
2. Perform the road test steps in sequence as identified in Vibration Analysis - Road Test in order to duplicate the customer's concern and evaluate the symptoms of the concern under changing conditions. Observe what the vibration feels like and what it sounds like. Observe when the symptoms first appear, when they change, and when they cease.
3. Determine if the customer's vibration concern is truly an abnormal condition or something that is potentially an operating characteristic of the vehicle.
4. Systematically eliminate or rule-out suspected vehicle systems.
5. Focus diagnostic efforts on the remaining vehicle system and systematically eliminate or rule-out suspected components of that system.
6. Make a repair on the remaining component, or components, which have not been eliminated systematically, and must therefore be the cause of the vibration.
7. Verify that the customer's concern has been eliminated or at least brought to an acceptable level.
8. Again perform the road test steps in sequence as identified in Vibration Analysis - Road Testing in order to verify that the vehicle has no more vibration.

Improper component routing or isolation, or components which are worn or faulty may be the cause of intermittent conditions that are difficult to duplicate. If the vibration concern could not be duplicated by following the steps of the Vibration Diagnostic Process, refer to Vibration Diagnostic Aids.