Live data describes values reported during the current diagnostic session. Freeze-frame or event data can preserve selected conditions associated with a stored fault. Looking at a healthy engine in the workshop today may not explain what happened on a cold start yesterday.
Match the evidence to the event
Ask which code or event the saved data belongs to. Record temperature, voltage, engine speed and load where available, keeping units and labels. Different controllers store different information, and a snapshot is not a continuous recording of everything that occurred.
Compare under relevant conditions
A useful follow-up test tries to reproduce the original conditions safely. An implausible value in one snapshot deserves investigation, but it does not establish whether the sensor, wiring, supply or interpretation caused it. The relationship between several readings may matter more than one number.
Do not clear codes simply to tidy the report before an appointment. Send both the saved event information and a description of the driver’s experience. If a garage has already logged live data, provide the original export rather than a photograph of a graph with no time scale or labels.
Related help
- Understanding pending and confirmed fault codes
- What to ask when a permanent fault code remains after repair
Browse all fault guides or use the vehicle module finder to prepare your enquiry. Send your vehicle details, what has gone wrong and any scan or test results. Contact us before booking or posting a module so we can check whether we can help.