Diagnostic Aids

WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

The misfire detection monitor is an on-board strategy designed to monitor engine misfire and identify the specific cylinder in which the misfire occurred. Misfire is detected using the crankshaft and camshaft position sensors. To determine if a misfire has occurred the PCM monitors deceleration of the crankshaft and compares the information received to engine speed and engine load. If a misfire event is determined, the PCM uses crankshaft position and the camshaft sensor signal information to determine which cylinder misfired.

The misfire detection monitor will be 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 will set a random misfire DTC.