01 · Investigate the concern
Diagnosis and assessment
We start with the driver's description, service history and the conditions in which the fault appears. Scan data points us toward a system; electrical and mechanical checks help distinguish the cause from a secondary code. A BMW misfire, an Audi boost fault and a Mercedes-Benz network warning need different paths through that process. We discuss why further investigation is appropriate, recommend an initial amount of investigation time, quote the cost and ask for approval before beginning. That quote covers investigation time rather than a guaranteed conclusion within the first stage.