DTC P0300: Random Misfire, Or DTC P0301-P0306: Cylinders No. 1-6 Misfire: Condition

Power Control Module (PCM) monitors Crankshaft Position (CKP) sensor input signal interval time. It detects a misfire in a specific cylinder by calculating change of CKP interval time for each cylinder. While engine is operating, PCM counts number of misfires that occurred during 200 crankshaft revolutions and during 1000 crankshaft revolutions in order to calculate a misfire ratio for each crankshaft revolution. If misfire ratio exceeds a preprogrammed criteria during 200 crankshaft revolutions, PCM determines that a misfire has occurred which can damage the catalytic converter, will set a DTC and will flash MIL. If misfire ratio exceeds a preprogrammed criteria during 1000 crankshaft revolutions, PCM will set a DTC and illuminate MIL when it detects malfunction during 2 consecutive drive cycles. Possible causes are:

• Secondary ignition system malfunction.
• Plugged or leaking fuel injector.
• Incorrect fuel pressure.
• Incorrect engine compression.
• Intake system vacuum leaks.
• EGR system malfunction.
• Fuel level sensor malfunction.
• Incorrect valve clearance.
• Incorrect valve timing.