استبدال الوحدة بأخرى من سيارة مختلفة

A used or transferred module fitted without being configured for the vehicle it is now in, so it runs software, calibrations or a security identity belonging to a different car. The module is fully functional and the fault is entirely one of identity, which is why every circuit test on it passes and the vehicle still refuses to work.

Three distinct failures live here and their codes differ. A version mismatch with the modules around it gives software incompatibility codes. A missing or invalid security credential — increasingly common as manufacturers pair modules cryptographically — gives certificate and authorisation codes. And component-specific calibration data is the quietest of the three: injector correction values carried over from another engine will run, badly, with no code naming the swap at all.

It is worth naming because of how often a used module is the reasonable choice. Salvage parts are legitimate and frequently the only sensible economics on an older vehicle. The point is that fitting is half the job — most modules must then be programmed to the vehicle identification number and have their calibrations written, and on security-paired modules that may require manufacturer access. Establish whether a module can be configured before buying it, because some cannot, and a used one that will never pair is scrap.