Operation CHARM: Car repair manuals for everyone.

Flow of Diagnosis

QUESTION THE CUSTOMER
The preliminary diagnosis begins with the service technician asking the customer enough diagnostic questions, especially those indicating conditions of noisy operation or vibration.
Always ask the customer about:
- The exact nature of the symptom. If it is a vibration, how is it felt? If a noise, what kind? Is it high-pitched, a rumbling noise or some other concern?
- The driving conditions in which the symptoms appear: road speed, drive or coast, on turns or on a grade only.
- Whether the condition is constant or variable. Does a noise increase in pitch with speed or some other factor?
All information should be written on the service order so the technician will know where to start looking. The technician doing the diagnosis must be able to identify the axle concern from what is written on the service order following the road test.
Have the customer demonstrate the symptoms in a road test whenever possible.

AXLE DIAGNOSIS CHECK SHEET
If there is enough reason to suspect an axle concern, the service technician should also initiate a customer concern evaluation.





Record all the information related to the concern in order to diagnose it accurately and quickly.