Sha-ul
NAXJA Forum User
- Location
- west of wichita, KS
I friend recommended this site to me, As he said there was a considerable knowledge base here, so I may have a mystery for you to help solve.
I have my Step-dads 1998 4.0 Cherokee sport in the shop, This started out as completely dead, would not start, with a code& symptoms indicating a defective crankshaft position sensor, Which I replaced, I was then able to start the truck, but it still ran extremely rough, at this point I ran out of time to work on it& took it to a shop I trust.
HE has had it& been working on it for a while, he has checked every connection, pulled every wire.
We sent the PCM in for rebuild but it came back as ok.
He was able to find some bad insulation& shiners in the transmission position switch, these he repaired, and the jeep now runs semi rough instead of shaking like a tree in a tornado.
Here's the stumper part when you unplug the transmission sub harness it smooths out. plugged in,it seems to run ok in drive, but if you put it into park or neutral it will set a code in a few minutes. My friend believes has isolated the trouble to the black/white wire from the pcm to the transmission control relay/ transmission control switch. at this point does anyone have have a schematic of the pcm functions, or have any of you encountered this sort of issue before? Are there any special resistance values that should be on the bk/w wire, or is the PCM just looking for a ground?
I have my Step-dads 1998 4.0 Cherokee sport in the shop, This started out as completely dead, would not start, with a code& symptoms indicating a defective crankshaft position sensor, Which I replaced, I was then able to start the truck, but it still ran extremely rough, at this point I ran out of time to work on it& took it to a shop I trust.
HE has had it& been working on it for a while, he has checked every connection, pulled every wire.
We sent the PCM in for rebuild but it came back as ok.
He was able to find some bad insulation& shiners in the transmission position switch, these he repaired, and the jeep now runs semi rough instead of shaking like a tree in a tornado.
Here's the stumper part when you unplug the transmission sub harness it smooths out. plugged in,it seems to run ok in drive, but if you put it into park or neutral it will set a code in a few minutes. My friend believes has isolated the trouble to the black/white wire from the pcm to the transmission control relay/ transmission control switch. at this point does anyone have have a schematic of the pcm functions, or have any of you encountered this sort of issue before? Are there any special resistance values that should be on the bk/w wire, or is the PCM just looking for a ground?