Jeep Garage  - Jeep Forum banner

Newest TCM flash. Don't get it if you're not having issues

11K views 58 replies 19 participants last post by  SkinnedArt 
#1 ·
We all know all the issues we have been having with shudder.

If you don't have issues DO NOT get this flash. Jeep changed the entire shift strategy to avoid shudder, in doing this they have killed fuel economy on anything other than flat ground.

I data logged to confirm my suspicion. If you have the cruise on in a hilly spot it's the most noticeable. The jeep will not allow more than 20% pulse width below 2000 rpm in gears 5-8 (that I have confirmed). so now instead of using tq to help up hills it bogs down and down shifts killing economy.

To say I am pissed that Jeep is "detuning" our vehicles to avoid design flaw is an understatement.
 
#13 ·
You are mighty quick to blame the update and the vehicle. Given the almost uniformly negative content to your postings, in this thread and others, I seriously question your objectivity and reliability to dispense advice in a controlled and unbiased manner. Perhaps a simpler explanation, but not one that would give you yet another opportunity to vent your spleen at Chrysler designers and programmers, is that your dealer didn't read the TSB carefully enough and reflexively erased your TCM's memory after the update--the previous recommended protocol--and your Jeep is now relearning your shift points. This would explain what you are observing.

I had the update performed and reminded my dealer not to erase the memory. I have noted improved shifting at lower gears and no discernible mileage declines. I think it is a good and worthwhile update.

You obviously hate your Jeep and want any reason to get rid of it. It is understandable given all of your problems. But in light of your obvious bias, perhaps you aren't the best person to provide advice to people who like me want to keep their Jeeps and are trying to make the best out of their purchases despite some unfortunate issues.


Sent from my iPad using JeepGarage
 
#14 ·
If ANYONE should be mad at Jeep, it is me. 62 days straight without my Jeep and 76 days to resolution.

My take on the TSB is that it does shift at a slightly higher rpm especially when the trans temp is cold, avoids lugging by downshifting a little easier, and modulates the lockup converter for a more gradual engagement. It fixed my shudder. My mpg seems to be about the same too...but my elevation changes are rarely more than 100 feet in my region.

Raven is pretty knowledgable...just not very tactful. I wish him the best and hope his demeanor doesn't hinder his efforts on a buy back or lemon law.
 
#26 ·
If this is being seen in our JGC you know damn well it will for the Ram 1500 as well which is too new to see a problem with the ZF 8 spd algorithms. I plan to stick around for a while and see how this goes with the Ram and Jeep.
I don't have but 4800 miles and no issue with shudder yet but will see if it shows up as reported by others.
Plan to instruct my dealership to not do that update.
My mileage is 28 plus on the interstate and don't want that dinked up.

Raven hope you find the perfect truck because I have not in any of the makes that the produce diesels. My SuperDuty was about as close to it as I could get but it still handles and stopped like a pig had the turn radius of a battleship but never one mechanical issue transmission and engine in 180K miles...
 
#28 ·
Jeep released two TSBs on Friday relating to transmission shift adaptation. The procedures suggest that certain kinds of work on transmissions may cause shift patterns to be unacceptable but that, as I read the TSBs, they will eventually self-correct. But for the impatient there are a couple of ways that the techs can goose adaptation in the right direction. All of the procedures require update of the TCM to the latest software first before going through the adaptation procedures.

http://www.wk2jeeps.com/tsb/tsb_wk2_2101214b.pdf

http://www.wk2jeeps.com/tsb/tsb_wk2_2103014.pdf


Sent from my iPad using JeepGarage
 
#33 · (Edited)
Well...I guess if we aren't going to be tolerant, nobody but coolaid drinkers will be left. Raven is a tuner who has spent his time and money cracking our ECU and datalogging. He still has his Jeep but I guess we just helped him decide. This is his thread...and Jeep did just what he said...detuned the bottom end to force an early upshift.

It would be different if he didn't know what he was talking about.
 
#34 ·
Sorry, ExcursionDiesel. Can't say I agree with you there. I wasn't questioning his knowledge or intelligence. And even the boy who cried "wolf" in the infamous Aesop's fable was ultimately and completely correct--just before the wolf ate him. The world is a tough place for petulant children.


Sent from my iPad using JeepGarage
 
#38 · (Edited)
Raven: FWIIW, you are on to something. Jeep has done the exact same things with the flashes for the 9 speed in the Cherokee. Something told me not to get any of the 9 speed flashes and for the most part my 9 speed shifts fine without them. Maybe it is a little rough around the edges but after all it is a Jeep and not a Lexus. Herein is my take on the problem. In an effort to increase sales and market share Jeep has tried to be all things to all people. Thus we now have mall cruisers and soccer mom Jeeps, front wheel drive, rear wheel drive and 4 cylinders for fuel economy. The crowd Jeep is catering to now is a different group than the hard core Jeep enthusiast. I just got done serving 3 months on a Chrysler/Jeep paid focus group. It was interesting that the number one complaint was that people's Jeep did not drive, ride, perform, or have the fit and finish of their previous foreign luxury vehicle. So what I think Jeep is doing to address this complaint is to basically detune our Jeeps as we know them and slowly turn them into luxury boulevard highway cruisers. I think Jeep is eventually going to wind up losing both groups in doing this, the hard core Jeep enthusiast and the cruiser group. My suggestion would be to return Jeep to its roots and relabel everything else Dodges. Make the Jeep perform like its heritage. If people want a super smooth shifter and great fuel economy buy the highway cruiser from Dodge. If you want a rugged vehicle capable of going off road and may ride, drive like that buy a Jeep. Chrysler/Jeep can throw all of the flashes it wants at Jeep transmissions. They will never get one that will satisfy both camps and that basically is the problem.
 
#39 ·
The problem isn't that it shifts like a Jeep. The 8 speed + high torque at low RPM diesel has an operational issue (shuddering) that affects a significant number of vehicles. A TSB to patch the TCM to compensate was needed. Unfortunately the solution is to avoid higher torque at low RPMs.

Fortunately the vehicle drives pretty well with the "improvements" but is a little more rev happy in hills and under hard acceleration.
 
#40 ·
Is it the TCM update that does it? There is also a PCM update and my Car is in the shop now and told them not to do TCM update as my diesel has never had a problem but that they should do the PCM one but if it cuts power in low end I don't want it


Sent from my iPhone using JeepGarage
 
#42 ·
The reason I ask this is because earlier I heard mention of a reduction in the pulse width of the fuel injection and to me that sounds like a PCM update
According to Raven, the knowledgable guy we ran off, the TCM monitors the pulse width % from the ECU (PCM) and anything over 20% now triggers a downshift. I'd avoid the TCM update if you haven't had any shuddering.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top