jwilson

Hi
I have an ongoing problem with my pcm. It was replaced a few months ago. The jeep stalls about once a day. You can press the pcm wires closest to the side of the jeep and it will start back up no problem. The wire connectors are not frayed, and the connectors latch in fine. When the pcm was replaced the mechanic only put in 2 of 3 bolts to hold it. I fixed that.
Has anyone heard of a problem similar to this? Maybe moisture or bad contacts? Are the wires easily replaceable? Any advice would be greatly appreciated.

Grand Cherokee, 4.0 v6 1997

ol"blue

Check the pins inside the connectors. Sometimes they're loose or corroded and need cleaning.
And Welcome to CF!

fantic238

...and zip tie the connector to the box.

jwilson

Thank you for the advice, I cleaned connectors and that helped. It is still stalling though. One other thing I forgot to mention. The ignition coil has two hairline cracks. i took it to my local shop and they said it tested in range. Since it tends to stall in the morning, is it possible it is the coil?


Thank you

fantic238

First of all, try to describe your stall more in detail.

jwilson

Thanks for replying. The jeep will randomly cut off. no check engine light, no sputtering. It will just die, sometimes after just being started and sometimes after driving for a while. There has been no discernable pattern. After replacing the spark plugs, wires, distrib cap, rotor, crankshaft position sensor, ignition coil, battery terminals, fuel filter and checking the battery we discovered that if you pushed in the pcm connections the jeep would start right up. If you pushed down on the connector closest to the side of the jeep it would cut off when running. It seems to be a good connection with very little wiggle room. The pcm itself was loose so we tightened it up thinking that the vibration could be working the connection loose. The jeep is running much better but sometimes will still stall at random times but not with the frequency it once did. That being said we need this to be a daily driver and do not completely trust it yet. We are thinking there is still something wrong with the pcm connection and would like any advice in how to ensure a solid connection.
Thanks

fantic238

I think it is not the connector, rather the PCM itself. You need another PCM to test it.
If it doesen't work we will diagnose wire per wire which one is not feeding, but first you have to try another PCM.

CrazyMacaw

I've been having the exact same issue with my 97 GC w/4.0.
I replaced the PCM and it ran stronger and got better mileage than it ever has for about 2 weeks and then started the same stuff again stalling randomly, some times not starting at all unless i went under the hood and pushed on the PCM sometimes requiring several attempts to restart.
I can push on this new PCM's cover just like the old one and get it to stumble and stall and it never sets a code, until today. I was pushing the cover of the PCM around connector 3 (gray one) and caused it to stall. I got codes 33 42 43 44 all of these circuits except the code 43 which is a general misfire code have wires coming from PCM connector 3.
33 = A/C clutch fault - pin 1 on the connector
42 = ASD relay circuit - pins 3 and 12 on the connector
44 = Battery Temp Sensor - pin 15 on the connector
My A/C was off and the engine and battery were cool.

I had the PDC cover off and my hands on the fuel pump and ASD relays in hopes of catching the ASD relay clicking if I caused a stumble or stall but it didn't click during the stumbles or stalls.

I have another "re-manufactured" PCM coming under warranty but I think perhaps that the PCM has a design flaw. I"m starting to wonder if any of the places selling these re-manufactured things actually open them up and do anything, I think maybe they just clean em up, reprogram as necessary, give them a quick bench test, and send em out.
I've read numerous posts from a variety of forums online from folks having the same type of PCM related issues all starting to appear somewhere after 90K-100K miles.


**UPDATE** 9/24//10

My second replacement PCM arrived today and I installed it. Fired right up and no wiggling of wires or connectors or pushing on the case will cause a stumble or stall. The first unit lasted 2 weeks, fingers crossed this one lasts longer.

cmsaw83

I know the chances of you responding with this post being so old is slim to none, but even so, I figure I'll shoot my shot...

I just wanted to ask you where, or who rather, you purchased your second re-manufactured PCM from? I'm looking for the name of the company, assuming the second one worked for you, and you had no further problems from it... At least, for a significant amount of time. I am experiencing that same problem, and have been through endless suggestions on posts on this and other forums, prior to reaching a point where I now feel it is time to bite the proverbial bullet, and spend the $300+ on a re-manufactured PCM. I need this Jeep to run, and to continue running. So, needless to say, after reading all the stories of re-manufactured PCMs being purchased, and installed, only for the owners to continue experiencing the same problem immediately after doing so, or within days to weeks (at most) after, I am a bit weary of choosing who to purchase the PCM from, by closing my eyes and just rolling with whichever company/item the cursor lands on. I feel I would be much better, at least attempting to vet a company by doing my due diligence, and asking someone, or a few people, who seem to have had some success in this area, exactly who it was they purchased their re-manufactured unit from.

So if you happen to receive a notification, or an email letting you know that I stopped to ask this question. I would greatly appreciate it if you could take a sec to share that info with me please. At your earliest convenience of course. Thanks in advance to you, or anyone else who may happen upon this thread, and have a suggestion to offer up while you/they are here, for your time and consideration.