Cause
Failed software update
A module left in an inconsistent state by a programming session that did not complete — interrupted by a dropped connection, a supply voltage that sagged during the write, or a tool that lost its session. The module is not broken; its contents are, and that distinction decides the repair. Reprogramming succeeds where replacement is merely expensive.
The codes it produces sound like hardware and are not. Checksum errors, memory faults and programming errors all name internal storage, and on a module that has just been updated they are far more likely to describe an incomplete write than a failed chip. A calibration verification failure on a module nobody has touched is a different matter and does suggest genuine corruption.
Voltage is the usual cause and the usual prevention. Programming can take many minutes with the ignition on and the engine off, and a battery that sags mid-write corrupts the block being written. Use a proper supply rather than a charger — a charger's ripple and switching behaviour are not what these sessions need. And check whether related modules were left on mismatched versions, since an interrupted session across a set often leaves one updated and the rest not, which presents as an incompatibility fault rather than a programming one.
Typically specialist work. Needs equipment or training most home workshops do not have.
Codes this can cause (5)
Codes where this is a likely explanation first, rather than merely a possible one.
Information, not instruction
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