the CKF is down by the crank.
The signal from one of the sensors in teh distributor and the signal from teh CKF is compared and if they dont match close enough you trip a code....anyway the CKF can be found on the drivers side of the engine, look for a wrapped bundle of 3 wires on the back side of the engine on the drivers side, it will be going down the side of the timing belt cover...you will probably need to pick up a haynes, chiltons or helm manual to be able to test it and know what results you need to see...unless it is just unplugged that is.