Originally posted by mercman:
The trimming is controlled by the crankshaft position sensor and the camshaft position sensor. Both of these are external and are easily changed,


Trimming???

Did you mean timing?

Also the timing is not controlled by either cam or crank sensor. Timing is 100% PCM controlled. It also uses several other inputs.

The crank sensor is used by the PCM for rpm determination and the cam sensor is only used for timing the injector pulses. (not ignition)

You are correct with the statement they are either good or bad. A wire may be intermittent though.
Either will throw a code for each specific sensor though.

Also the engine most likely won't even run with a bad crank sensor. It will technically limp along with a bad cam sensor.

2000 SVT #674 13.47 @ 102 - All Motor! It was not broke; Yet I fixed it anyway.