You're computer needs to see both a crank speed reading and cam position reading for it to tell the coils to fire a spark to the plug.
Since you've checked spark and fuel pressure, use an automotive stethoscope to listen for your injectors firing. You'll hear a distinct clicking sound. If your injectors are firing, the valve timing may be off (bad timing chain). You can verify this by doing a compression test.
If your timing chain has slipped, just replacing the timing chain wouldn't be economically sound, as that would be like putting a band aid on a gunshot wound. The rest of the motor will be just as worn as the timing chain. However, I do not recommend rebuilding this motor unless you want to keep this truck for 10 more years. There are too many low-mile used engines for dirt cheap.
It isn't your ignition switch. If that were the case, you wouldn't be getting spark at the plugs. Your ignition timing is controlled by the computer. If that's out of wack, your computer would be bad. Sometimes an intermittent fault with your sensors will fail to set a code. Depending on which sensor is faulty, the computer will have to determine it has been faulty for a certain amount of drive cycles or time. If the sensor acts good, the computer will shut off the light by itself.
If a scan doesn't produce anything, you'll need to continue your diagnoses on the systems components the computer can't always read. These would be the mechanical components of the engine.
If the crank sensor was bad and to replaced it the sensor will sometimes need to be programmed to the car a shop can do this for about $130.00.
Tuesday, February 1st, 2011 AT 11:59 AM