Code P0300: Random/Multiple Cylinder Misfire Detected

Code P0300 (Random/Multiple Cylinder Misfire Detected) sets when the ECM's crankshaft-acceleration misfire monitor counts combustion events across multiple cylinders (or an undifferentiated pattern) beyond the calibrated threshold, including variants triggered by a low fuel level, a cold-start window, or a commanded fuel cutoff. Because no single cylinder is isolated, the cause is almost always something that affects the whole engine at once: a vacuum leak, worn spark plugs across the set, a weak fuel pump/low fuel level, or a base ignition timing/reluctor fault.