Build a repeatable description
Record whether the engine is cold or warm, the selected gear, road speed, engine load, AC setting and the exact dashboard message. If the concern is intermittent, a short video with the date and sequence can preserve evidence that may disappear before the visit.
Do not clear codes or disconnect the battery just before diagnosis unless the vehicle information requires it for safety. Clearing stored history can remove timing and voltage clues.
If the oil-pressure, overheating, brake or steering warning is serious, or the car cannot be controlled safely, stop in a safe place and ask us to arrange the right way to bring it in.