DTC P0300:00: Notes

DTC P0300:00 (MZR 1.5) DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0300:00	Random misfire detected
DETECTION CONDITION	The PCM monitors the CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If change of interval time exceeds the preprogrammed criteria, the PCM detects misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the PCM determines that a misfire, which can damage the catalytic converter or affect emission performance, has occurred. Diagnostic support note This is a continuous monitor (misfire). The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. The MIL flashes if the PCM detects the misfire which can damage the catalytic converter during first drive cycle. PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	Erratic signal to PCM APP sensor signal malfunction ECT sensor No. 1 signal malfunction IAT sensor signal malfunction MAF sensor signal malfunction CKP sensor signal malfunction TP sensor signal malfunction VSS signal malfunction Related connector or terminals malfunction Related wiring harness malfunction CMP sensor malfunction CKP sensor looseness Ignition system malfunction Spark plug malfunction Ignition coil related wiring harness malfunction Ignition coil malfunction Erratic signal to ignition coil Excessive air suction in intake air system (between MAF sensor and intake manifold) MAF sensor contamination Fuel supply system malfunction or improper fuel line pressure Fuel pump unit malfunction Pressure regulator malfunction (built-into fuel pump unit) Fuel leakage in fuel line between fuel distributor and fuel pump Restricted fuel line blockage Restricted fuel filter blockage Fuel runout Improper operation of variable valve timing control system Purge solenoid valve malfunction Engine internal malfunction Engine coolant leakage to combustion chamber Insufficient engine compression EGR valve malfunction (stuck open) PCV valve malfunction Poor quality fuel PCM malfunction