Misfire Monitor Operation

WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 2007 Mercury Mountaineer, 2007 Mercury Monterey, 2007 Mercury Montego, 2007 Mercury Milan, and 2007 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.

There are 3 different misfire monitoring technologies used. They are low data rate (LDR) and high data rate (HDR), and neural network misfire. The LDR system is capable of meeting the federal test procedure monitoring requirements on most engines and is capable of meeting the full-range of misfire monitoring requirements on 4-cylinder engines. The HDR system is capable of meeting the full-range of misfire monitoring requirements on 6 and 8 cylinder engines. The neural network misfire detection system improves detection ranges and cylinder identification for a wider range of misfire patterns on some 8, 10, and 12 cylinder vehicles. The HDR on these engines meets the full-range of misfire phase-in requirements specified in the OBD regulations. All engines except the 6.8L V-10 are full-range capable. All software allows for detection of any misfires that occur 6 engine revolutions after initially cranking the engine. This meets the OBD requirement to identify misfires within 2 engine revolutions after exceeding the warm drive, idle RPM.