It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.
Possible Causes :
Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.
Diagnostic trouble code P1A78 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before P1A78.
Fortunately, P1A78 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.