Help with PCM

Hey guys my check engine light came on and i got it scaned its Code "P0605"
interal controll modual.... but when doing the scan the mechanic noticed 3 of my distributer caps were not fully on could this have been the problem...he didnt know if it could be. he said i would prolly have to change my computer .. does this make sense to anyone? and how much would this cost? I have a 95 Ford Ranger 2.3L

"PCM's" are pretty rugged ... but they do occasionally fail. I would bet on other things first:

Start reading here:
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0b/97/cc/0900823d800b97cc.jsp

Be sure you cover all the subsets ... especially the "diagnostic trouble code charts".

Generally the computer isn't the problem connect your plug wires. Disconnect you Neg. battery cable for 90 seconds. The problem should go away.
Normally the computer will not advance timing when bad. Mark your timing marks look where it is at idle and if when gunning the motor it won't move the mark do further checking.