An ECU label can be useful, but it is not the whole identification story. A housing may have been replaced, a used unit may have been fitted, or the visible number may not describe the software actually inside the control unit. That is why a request should combine label information with diagnostic output, read-tool data, file metadata and vehicle context. For example, Simos as a family tells a provider something different than simply Continental, while Bosch MD1 and MG1 point to different technical expectations than older EDC families. If the workshop is unsure, the request should preserve that uncertainty. A professional provider can often work with uncertainty when the evidence is attached; guessed certainty is harder to correct later.