Prepare for diagnosis
A fault with no fault codes: how do you prepare for diagnosis?
Jerking, loss of power or a vibration, with no useful fault code? Clarify what was scanned, then gather the facts a professional needs.
Diagolia guides
Guides by symptom
Learn to describe observed symptoms, distinguish starting problems and prepare useful information for professional diagnosis.
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Prepare for diagnosis
Your car will not start. Begin with what happens.
Before looking for a part to replace, describe what happens. Three situations help you decide what information to pass on; none is a diagnosis on its own.