Chrysler Repair: P0320, jeep cherokee sport, volt supply

Question
Got this code from my pocket scanner for my 1997 jeep cherokee sport and it says ignition/distributor engine speed input circuit.  What does this mean, where is it located, is it easy to fix it yourself?  Thanks for taking your time for answering this question.

Answer
P-0320 NO CRANK REFERENCE SIGNAL AT PCM

POSSIBLE CAUSES
CKP SENSOR GROUND CIRCUIT OPEN
CKP SENSOR
5-VOLT SUPPLY CIRCUIT OPEN
5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
CKP SIGNAL CIRCUIT OPEN
CKP SIGNAL CIRCUIT SHORT TO GROUND
CKP WIRING HARNESS AND CONNECTOR
CKP SENSOR CONNECTOR TERMINALS
PCM (NO CRANK REF SIG AT PCM)
CKP WIRING HARNESS & CONNECTOR INTERMITTENT
PCM CONNECTOR
INACTIVE TROUBLE CODE