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TSB - Shift improvements for 2014 3.0L Diesel (Feb 28/2015)

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2014 2015
12K views 59 replies 28 participants last post by  Roadkill 
#1 ·
#3 ·
I'm thinking I'll give this a shot, but...

Less than desired engine braking during downhill descent.
Haha, I have the *opposite* problem. I have never driven a vehicle that required more power to go downhill. All too often I find myself shifting to N to keep from slowing down.

Parking garages are the worst. Really have to give it a lot of accelerator pedal encouragement to have the Jeep obey gravity. I usually just coast in N instead.
 
#6 ·
Please read the first paragraph of the TSB. Jeeps's revision TSB's mark the added features in that TSB with asterisks, so the only item this revision fixes on top of the previous one is the Eco memory retaining feature.
 
#12 ·
From new, I never had any issues with the tranny or ECO mode on my GC diesel. It always shifts smoothly and gets great mileage....

Having supervised software developers before I retired, I learned that in SOME CASES a re-flash can exacerbate issues rather than fix them. So, given the history of previous Jeep re-flashes, I chose not to get it done....YMMV:thumbsup:.

Glad y'alls are working fine......
 
#13 ·
My shifting is horrible and has been so for the past year.

During slow acceleration from a stand still I get excessive engine braking when releasing the throttle a little - makes for a very jerky ride.

Has also ruined my fuel economy. I get 11L/100km or 21 mpg around town.

I really hope this fixes it..

Love the diesel but
 
#14 · (Edited)
My shifting is horrible and has been so for the past year.
Haha, there's normal horrible and then there's "Jeep horrible". Does your Jeep lurch when it shifts 2-1? As in "holy crap, I just got rear-ended!"? I had that fixed by the late August 2014 flash (it worked for that).

During slow acceleration from a stand still I get excessive engine braking when releasing the throttle a little - makes for a very jerky ride.
Please let me know if you ever get this fixed. Or start a new thread for others like us... this EcoDiesel has the most engine braking of any vehicle I've ever driven.

EcoDiesel: "Oh, so you want to go down a steep grade at 35 mph? Well, you better step on the accelerator if you don't want to lose speed."

I often shift into N to avoid that kind of engine braking and to be able to coast.

Has also ruined my fuel economy. I get 11L/100km or 21 mpg around town.
I'm getting 13-15L/100 km around town now that it's a bit warmer.
 
#23 ·
Had the flash done while my truck was in the shop last week for front wheel bearings. I have to say there is a noticeable improvement, especially when on cruise control. Never had any of the low speed problems people are talking about. This was my 2nd transmission flash.
 
#24 · (Edited)
This was my 2nd transmission flash.
Thanks for reporting in. However the question is whether this latest flash adds anything except Eco Mode persistence. Was your first flash of the next most recent TCM release, i.e. the one that came out at the end of August 2014?

Based on the TSB, it would seem that the Aug 2014 TCM flash update had various shift fixes, but the Feb 2015 release simply adds Eco Mode persistence in addition to the fixes in the August 2014 release.
 
#25 ·
Yes, exactly. I had the one in August done. My Eco still doesn't persist, but the car longer down shifts two gears when accelerating on cruise control.

I haven't noticed any other differences, but really didn't have any issues besides CC.
 
#28 · (Edited)
Yes, exactly. I had the one in August done. My Eco still doesn't persist, but the car longer down shifts two gears when accelerating on cruise control.

I haven't noticed any other differences, but really didn't have any issues besides CC.
So, what I'm hearing from you and Silvermax is that:
1) This TCM flash does not implement the only thing the TSB claims the flash implements (i.e. Eco Mode persistence), and
2) No one has any idea what this TCM flash actually changes.

Chrysler: "Do you feel lucky... punk?"
 
#32 ·
Maybe I'll give the flash a shot. I just had a really crappy experience in traffic today. Floored it from a standstill in Sport mode and had an "excellent" double-lurch that literally jerked me and my passengers around.

Should have done a brake-spool-turbo launch instead.
 
#33 ·
So after driving for a little more than a week with the flash, I can say that the car will stay in taller gears longer now (which I love) and use the turbo more, rather than down shifting at the slightest hint of accelerator pedal.
 
#36 ·
Had 21-012-15 performed the other day. Shifting does seem to be improved but maybe it's wishful thinking. Need more time to eval... Mileage is still good, 28-30 highway. ECO setting still resets during power cycles. FYI, had a 200c loaner and the 9 speed shifting is terrible...
 
#38 ·
Had 21-012-15 performed the other day. Shifting does seem to be improved but maybe it's wishful thinking. Need more time to eval... Mileage is still good, 28-30 highway. ECO setting still resets during power cycles. FYI, had a 200c loaner and the 9 speed shifting is terrible...
Update: After driving a week plus I do believe shifting has been improved though I still would prefer that the tranny wouldn't downshift so fast when accelerating especially since I have the diesel with plenty of torque, it seems unnecessary during highway maneuvers.
 
#37 ·
I had the latest flashes installed today: PCM, TCM, and amplifier (who knew? the amplifier has software). I can confirm that the Eco-mode is still not persistent across a power cycle. Since that is the only item flagged as new, it does make you wonder what function really is in the latest TCM flash. I was not having any real transmission issues, I just figured it would be good to get the update since it seems to fix odds and ends. I have a big trip upcoming towing a travel trailer (about 5,000 pounds) and thought improved engine braking would be good. And getting the latest PCM update makes sense to avoid exhaust errors.
 
#42 ·
Ugg. My JGC Diesel had been running perfectly on the original PCM software when the car was delivered. Jeep dealership just installed some new PCM flash during some recall work and now the car bucks and stutters in the 2-3 gear range. So annoying.

Any way to tell what they flashed my car with?
 
#44 ·
Just got the update. Never thought I had problems with the transmission, but surprisingly smoother shifting now.
 
#45 · (Edited)
I am back from a couple thousand miles of towing a 5000 pound travel trailer to/from the mountains of California with the latest PCM and TCM updates. I had no problems and the transmission shifting was great. I was really surprised to discover that the cruise control automatically downshifted as needed to provide engine braking going downhill. I highly recommend the latest updates.
 
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