'99 PCM issues
I'm doing some work for a friend on her '99 Sport, 4.0, auto, w/o SKIM module. It gives a P1686 code which is a SKIM error. The jeep was having issues which I believe I traced to a crank position sensor which shorted to the exhaust manifold. It would run intermitantly than finally quit altogether. In this stage it would accasionally give a "No Bus" display in the odometer window. Since I replaced the crank sensor with new it will only run about 2-3 seconds then quit and then the P1686 code can be detected, (No "Check Engine" light is displayed). By looking at the schematics the only things that I can see that have anything to do with a possible SKIM error are input from the SKIM module, (which this vehicle doesn't have), the clock spring, (which is only about 3 months old and no other typical clock spring problems), and the data connection. I'm guessing that the PCM was corrupted by the shorting and that a new, reprogramed PCM would resolve the issue. My concern is that some of the exchange sources have less than good reviews and I don't want to hang out $300 without being able to recover at least most of it. I also got some input from another Jeep shop that ANY problem referring to SKIM issues needs to go to a dealer. Any thoughts?
'05 Rubicon/Sahara 6 spd; '08 Liberty Sport 3.7, auto; '79 J20 360, 4 spd, "Glade8r"; '63 J200 Thriftside, 230 OHC, 3 in the tree; '46 CJ2A s/n 42426; '46 CJ2A s/n 29968, column shift