Detection Condition

WARNING: This page is about a different car, the 2003 Mazda Protege5 and 2003 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.

PCM monitors Crankshaft Position (CKP) sensor input signal interval time. PCM 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 occur during 200 crankshaft revolutions and during 1000 crankshaft revolutions in order to calculate misfire ratio for each crankshaft revolution. If misfire ratio exceeds a preprogrammed criteria, PCM determines that a misfire has occurred which can damage the catalytic converter and will set a DTC. This is a Continuous Monitor (CM). MIL illuminates if PCM detects which affects emission performance in 2 consecutive drive cycles. MIL flashes if PCM detects misfire which can damage catalytic converter during first drive cycle. Pending code is not available while MIL is flashing. Freeze Frame Data is available and DTC is stored in PCM memory.