A useful diagnostic starts with your description of the problem: when it happens, what changes, and what has already been tried. Testing helps narrow down causes rather than treating every symptom as a failed part. Intermittent issues may need a different approach from a consistent fault. Bring any relevant service history and describe the symptoms as clearly as possible.
Your vehicle is different.
This is general information, not a diagnosis. Get in touch to discuss your vehicle and confirm the appropriate next step.