I was able to clean my ECM this afternoon and it looks like it has solved the problem with my Jeep being stuck in "limp home mode."
If you are experiencing the same problems, I do recommend that you read the thread above and attempt this if you are comfortable doing so. The electronics cleaner that I purchased from Autozone in Atlanta was $4.99 -- which is a lost less expensive than replacing a $400-$600 part.
What I am gathering as well is that ECMs are being replaced unnecessarily. For some reason, the design of the Chrysler version is more prone to accumulating graphite -- which is interrupting the flow of electricity on the circuit board and thus triggering the onboard computer to generate an error code, which puts the transmission in 3rd to indicate to the owner that the car should be taken into a shop and looked at by a mechanic. Kind of the automotive equivalent of Windows Safe Mode (Sidebar: I may not have the specific details and terminology correct here, but I understand this to be the basic premise).
So, yeah, if you run into this problem and have a basic working knowledge of cars and/or follow these instructions slowly and carefully -- then you can avoid paying the $400-$600 for a new ECM part or the $800 - $1100 that seems to be the going rate for parts + labor. After performing this procedure as well -- even if my ECM was bad, I knew I could at least order the part and put it in myself versus taking it in to a mechanic. The caveat being that you have to be careful not to throw parts at a problem if you're not absolutely sure that replacing those parts will correct the problem --otherwise it can get expensive and you're better off taking it to a mechanic who can diagnose it properly. Having said that, this specific issue does seem to be a recurring problem for Jeep owners...
So, for me, these are the takeaways -- between the points made above and my own experience:
*Visit this link to gain an overall understanding of the problem as well as a detailed procedure for removal -- http://www.cherokeesrt8.com/forums/s...ad.php?t=32822
*This individual was nice enough to put together a video showing how to remove then reinstall the unit --
*When removing the base unit you'll need a Torx socket to remove the screws. These are typically included in the larger socket wrench set kits -- they are somewhat star-shaped and the size of a screwdriver head. Do note that this is different from a regular screwdriver head or allen wrench. I have attached a photo for your reference -- that small set, included in my socket wrench kit, represented everything I needed. My apologies for not taking note of the exact sizes that were used.
*Of course, remember to take your time -- it's best to be slow and gentle so nothing gets broken
*To remove the gear shift knob -- hold the conical base firmly, then twist the top part of the knob about a 1/4 to a half turn. You should then be able to pull the knob up to remove it. (Shift Knob Removal?
*After applying the electronics cleaner to the board -- I could not find any specific mention (on the back of the can or on the web) of how long you should allow for the cleaner to dry. The can seemed to suggest that you wipe away the excess shortly after applying it and that the cleaner is designed to evaporate quickly. I just let the ECM sit out (this was inside my home in a clean environment) on some paper towels for about 30 minutes -- and it seemed to work just fine.
*One thing that did concern me was that, when I removed the ECM and actually saw the board -- that it looked to be relatively new and clean (my Jeep has 109K on it, as of this writing, and I purchased it at 75K -- so I have no idea if this was the original ECM or not). I did notice some grey residue on the paper towels as I did clean the ECM. Not a substantial amount, but enough where I noticed it. This seemed to be the culprit, even in this small amount.
*Going forward, I'm not going to use the Tiptronic feature on my transmission again. Maybe I am overreacting a bit -- but using this is what triggered all of this and, in a car this size, I really don't have a reason to use it anyway. I suppose, in theory, now that the board has been cleaned this should not be an issue -- but it's not worth the risk and inconvenience.
*Great tip as well - turn your key ignition off and on (not all the way to the START position, just to ON) 3X to read error codes generated from your check engine light
*Oh and **VERY IMPORTANT** -- After I replaced the ECM and took it for a test drive, the check engine light was on and the transmission still was stuck in 3rd. I then, taking the earlier advice from the poster above, disconnected the negative battery terminal, turned my ignition key to the on position for 5+ minutes, turned it off, reconnected my negative battery terminal, then started up the car. This cleared out the memory of the onboard computer, the check engine light disappeared, and my transmission was shifting properly again.
Anyway, just sharing some of the details I encountered in my experience over the last 24 hours.
I have since test driven my Jeep and everything keeps working fine. I *will* write a follow up post if I continue to have issues -- but, if you don't see a follow up message from me -- then this issue has not recurred.
Thank you again to the person who shared the link above. Hopefully this can save others time, money, and unnecessary repairs as well.