Engine Crank/Engine Running
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
During engine crank the PCM fires 2 spark plugs simultaneously. Of the 2 spark plugs simultaneously fired, one is under compression and the other is on the exhaust stroke. Both plugs fire until the camshaft position is identified by a successful camshaft position (CMP) sensor signal. Once the camshaft position is identified, only the cylinder under compression is fired.