Failure Conditions

PCM detects misfire as a change in angular acceleration of crankshaft. PCM will monitor for misfire when following conditions are met:

• Engine has been running for at least 5 seconds.
• Engine speed is 500-6000 RPM.
• Engine coolant temperature is more than 14°F (-10°C).
• Intake air temperature is more than 14°F (-10°C).
• There is no sudden acceleration/deceleration such as occurs during gear change.

PCM sets DTC P0300 and turns MIL on when misfire has occurred more than 200 out of 1000 crankshaft revolutions.

If catalytic converter temperature is more than 1742°F (950°C), and misfire occurs more often than allowed in last 200 crankshaft revolutions, PCM determines severe misfire exists and will set DTC P0300 and cause MIL to blink.