Cause
Battery disconnected or gone flat
The battery disconnected or fully discharged, so modules lost their stored data. It is usually a recorded event rather than a fault — the codes describe what happened, and the vehicle may be entirely healthy.
What is lost varies and matters. Adaptations, learned idle and fuel trim values, radio codes, steering angle and throttle positions. The vehicle can drive poorly for the first miles afterwards while it relearns, which owners often report as a fault caused by the battery work.
A flat battery is different from a disconnected one in one important way: it is a symptom. A battery that goes flat by itself has either failed or is being drained, so the useful question is why. Clear the codes, let the vehicle relearn, and see what returns — codes that come back describe a live fault, and those that do not were the disconnection. Some systems need a deliberate relearn rather than time, so check whether a procedure is required before concluding the vehicle has settled.
Typically an easy fix. Often worth checking before paying anyone to look.
Codes this can cause (3)
Codes where this is a likely explanation first, rather than merely a possible one.
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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