Well a variety of ills beset her, so I started looking hard at the PCM and decided after watching several YouTube videos, to take it apart and have a look. Which actually I did once not long ago, just wanted to have another look. What I think is the front pcb board, that comes off easily, is the voltage regulator section, and the back half that’s potted into the dish of the box with rubber, is the business end. Ok. So.

I took it off and apart, then they said that if you heat the back the rubber will loosen up and you can pry the whole mess out, clean it up, and actually look at the circuitry, solder joints, etc. Baloney. That thing is in there with some sort of rubber that is made for underwater exploration, it is NEVER going to let loose. So not to be discouraged, I cut the corners with tin snips, and pried the sides all the way down. There. Nope still wont budge. So I took my reciprocating saw and cut it out. LOL! Well out it finally came in a crumbly mess. They said Acetone will dissolve the rubber. Nope. Soaked it overnight and it just laughed at me. Like cement. By this time I could see that my efforts had dislodged a couple of the traces from the pcb, and maybe a component or two. I could also see that there are little tiny resistors and the like, surface mounted absolutely everywhere. Some so small the naked eye can barely detect them. Just a TON of them and way small micro printed circuits too. Ugh. Chances of finding or fixing anything on this are slim and nil.

Still undaunted I was thinking maybe just replace the 3 big electrolytics that were sticking up. Nope. Embedded in the cement like never to be dug out. Grr. I once again stepped back and looked at my 2 days of efforts and decided I was up the creek with no paddle.
Went on Advanced online and there, at the corner store, in stock yet, was a Cardone refurbished pcm. I ordered it online and saved 25, yes 25%. I put the remains of my experiment back together somewhat, and in half hour was looking at my new rebuilt pcm, looking pretty in the box. They accepted my core and refunded $90 on the spot. So the whole deal cost me just about $140.
Hell, I thought, it's not even 9 am and here Im ready to be back on the road with this thing . Deal.

The 96 and 97 are just plug and play, no programming of the mileage or VIN because that is in the BCM, and the was no skim in 96-97.
So just out of the box and plug it up. Well I did take tome to clean connectors and stuff obviously.

Fired up and ran ok, Took around the block came back and did some frame welding. So today I took it on its maiden voyage, across town.
Perfect on the highway. I was having shifting issues and premature TCM lockup and now it drives so much cleaner and nicer.
As far as the voltage regulator I had already installed the Chrysler external regulator a couple weeks back and am so happy with that I left it just as is. Charges 14.4 all the time even idling with everything on. That regulator also compensates for temperature so good there too.

All in all I should have done this a long long time ago but was afraid to pull the trigger on an Ebay rebuilt. With Advance you can always argue yourself to another unit if it was defective out of the box or at least get a refund.

Very pleased. I will take questions now. heh
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Follow up: After 4 days and a bunch of all kinds of driving, the transmission has not missed a single shift. So before you condemn your 42RE, take some consideration of the PCM! So much more drivable.

 

It will be interesting to see how long it holds up. I have heard some good and bad things about Cardone PCM.s, but hey were for WJ.s I did learn something important and that is the 96&97 dont need to be programmed. Thats a huge consideration. I wish I liked the ZJ body they seem way more dependable and less trouble prone than the WJ.

 

To be honest, I don't anticipate it failing. I have read that most pcm failures are because of user abuse, disconnecting without disconnecting the battery, or huge problems with the supply voltage such as the battery being disconnected with the vehicle running. Also I forgot to mention that the one I butchered with the sawzall, was for sure a rebuilt itself. So the PO had put it in and it was bad from the day I got it.

 

You have to remember that these are old parts and constantly on use. They are just like any mechanical or electrical device that has an expected useful life. Mine crapped out and I didnt do anything to cause it and that happens to a lot of people. I not willing to believe that thousands of PCMs fail because the vehicle owner abuses them. It sounds to me that ZJ PCMs are much simpler in design because they have less to do than those on the WJ. I'd be much happier owning a vehicle that had no PCM at all to worry about.

 

Thanks for straightening me out.