Pinpoint Test AR: Random Misfire Detected: Introduction: Detection/Management
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Ford RV Cutaway, 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Econoline. However, it is still accessible from the selected car via links, so may be relevant.
The misfire detection monitor is enabled only when certain engine conditions are satisfied. If the PCM is unable to detect which cylinder is misfiring or multiple cylinders are misfiring the PCM sets a random misfire DTC.