Based on my, and many others, experiences, the problem will certainly reappear, at some point in time. The 'repair' is most likely related more to removing and reconnecting the 'A' connector, the one on the driver side of the computer and not to the cutting of the screws. The screws go into a piece of plastic which is near to 3/4 inches deep and has little, if any, lateral stress anywhere. If you want to try to make the computer fail, push in (toward the firewall)hard on the top driver's side of the ECM. It will almost certainly stall. Nothing special, hot or cold, day or night -- just press hard with your thumb. If the car doesn't stall (very unlikely), then you are not one of the unfortunate ones. On the other side of the coin, if you force the driver's top of the ECM toward the front of the vehicle with something (like a 3/4 inch hot water PVC pipe elbow) you will likely be unable to make the failure occur , no mater what you do. Fixed? Of course not! It just tells you that the computer is indeed defective. Please see my post at # 117, and others, because replacing the computer is not only expensive, it's not always that simple. The replacement needs to be a properly programmed to your VIN# unit that is suitable for your vehicles wiring. Mine was a 406AB and nothing higher than a 406AC would accept the proper programming, causing the truck to start, but not RUN. Unless you know if your vehicle has had any ECM 'updates' installed, it is probably safest to get only the base programming done.
The worst thing about the majority of these failures is that THEY SHOW NO FAILURE CODE. The reason for this is almost certainly that the BATTERY VOLTAGE (going in at the 'A' connector) is being lost and the computer doesn't see any error, it just goes to sleep and then starts working again when and if the problem (loss of voltage)goes away.
Regards,
Jim
Found that the outboard PCM cover screw was shorting out the circuit board. Chrysler PCM p/n P56028412, s/n TEH106636023.
Short story long: I have a 96 Grand Cherokee 4.0L, 125,000 miles. Several weeks ago, I started to have stalling issues. Hot or cold, dry or wet, first drive of the day or last, it didn?t matter. The engine would cut out. It felt like it lost all electricals.
At the time it was showing an ASD relay code. Swapped the ASD and A/C relays. Same problem. I didn?t have time to look at it, so I had the dealer go through it. After 2 days and $200, they called and said it was the ASD relay, and that they put in a new one, and it?s all good. Um, ok, maybe I missed something. I?m a trusting soul, but let?s see if this fixes it. The next day the problem was back. I went back to the dealer and they basically said, ?We don?t know what it could be, good luck with that?. Now my wife knows why I don?t go to the dealer. By the way, the old relay tested good.
My turn. Being the methodical aircraft mechanic that I am, I grabbed a multi-meter, contact cleaner, and wiring diagrams. I cleaned connectors, ohmed out wires and sensors, checked for power and grounds. Everything checked good. By now, it?s showing ASD, crank sensor, and primary ignition codes. Then, with my wife trying to start it, I wiggled the connectors on the PCM. Every time I wiggled the gray C3 connector just right it would run. When I let go, it would die. So I took the connectors apart and tightened up the crimps (I don?t recommend doing this without the proper extractors and crimper). Threw it back together and BAM! Same problem. Well, time to bite the bullet and check for bad solder joints on the PCM board. I took the cover off of the PCM and realized that looking through the potting compound is like looking through Guinness Stout. But, I put it back in and hooked it up. It started stronger than ever, and didn?t even think about stalling. Yes! I figured that I finally got the connectors sorted out, so I left it over night to cool down. Got up the next morning and it started right up and wouldn?t stall even when wiggling the connectors. So I put the cover back on, put the PCM back in, hooked up the connectors, and BAM! It wouldn?t start! That was the point when my wife asked, ?How?s it going?? And I, being the methodical aircraft mechanic that I am, said, ?what the ----?? That?s when my wife turned around and went back into the house. While smoking a pack of cigarettes, I thought, ?Gee, it runs with the cover off, but not with it on.? DUH, wonder what it could be? So I backed out the two screws that hold the cover on and BAM! It started right up. Then, while it was running, I tightened the outboard screw and sure enough, it died. Yes! Aircraft mechanics love it when they can make things stop working. I installed new screws (1/4? long, factory screws are 1/2? long Torx head), and she?s been running great ever since.
Now, will this fix a bad crank sensor or idle air motor? No. But it is an easy trick to try before going to the dealer and having them throw expensive parts at your Jeep and seeing if any of them stick. Just back out the cover screws about 1/8?-1/4? (don?t worry, nothing will fall apart inside). If it fixes it, great! Spread the word. If not, use logical trouble-shooting steps. Learn the systems ? what will and what won?t cause the problem. Good luck.
As a side note, if you want to see a service manager?s eyes pop out of his head, tell him that you want your money back because your not going to pay them to trouble-shoot a design defect. It?s a glorious sight.
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Closed as of March 23, 2018.

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