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Unread 09-08-2007, 02:33 PM   #46
Gramps
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If you don't have the stumble or need the low end performance gain I think that I would hold off. unibus said that he saw a 1.5 mpg increase and I'm trying to verify that with mine. Only 1 fill up so far after hot rodding around and then taking it easy and so far I don't see a big change in mileage, nothing abnormal anyway. Give me a couple more tankfuls to really check. If the mpg stays the same then I can see no reason not to have it done. The improvement to low end performance is certainly worth it for me. For those that aren't concerned about a possible change in mileage then I would say go for it.

The lack of hp on the top end is just the way it is. You have to sacrifice something to get decent mpg.

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Unread 09-08-2007, 04:22 PM   #47
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i usually use it at the city stop run, stop run, thats why i am thinking of that lack at low speed
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Unread 09-08-2007, 04:40 PM   #48
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Then I think that you would enjoy the benefit of having it done. If more low end is what you're looking for this is a definite improvement.
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Unread 09-08-2007, 07:34 PM   #49
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So it does give you more low end power. That's what I find I need. Unless you are "standing on it" when you take off (like my wife does) I find our Compass a little "soft" on low end. Guess I'll have to talk to my dealer and see what they know or don't know about it. Wish me luck Gramps.

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Unread 09-08-2007, 08:14 PM   #50
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It "feels" as if you've changed gear ratios. In a rear wheel drive it would feel like going from 3.23 to 3.55 or 3.71, not enough to peel your paint but it's there. More responsive and smoother too. I certainly don't need to stand on it any more and by the time that I hit 50 or so I'm settling down to cruising speed.

I also had a concern about taller tires killing what low end I had, now I feel that I can sacrifice a little bit of it and go with something in the 28" range. I'm very happy with it!

GOOD LUCK!
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Unread 09-08-2007, 08:17 PM   #51
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Quote:
Originally Posted by Gramps
unibus said that he saw a 1.5 mpg increase and I'm trying to verify that with mine.
Over 4 tanks so far it's looking like 1mpg increase. Not earth shattering but it has improved. Still worth it to me for the improvements other than mileage.
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Unread 09-09-2007, 06:36 AM   #52
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It will help on the highway as well. It does not require as much pedal travel to pass another vehicle. If you want more top end power, slap on the K&N Aircharger, I feel it helped quite a bit on top end. (and well it should!)

Again, by the way that Chrysler named this TSB and the way my Compass feels, this is not a power increase in any way. I doubt they changed timing in the engine. If they did, it wasn't much.

What they did do, is change the "perceived" power. They did this by making the CVT transmission react to the pedal much quicker. It also is more performance oriented now, by this I mean it stays in "gear" longer. I say "gear" because the trans uses a belt/pulley system, not gears.

This design, by nature, WILL increase MPG if you keep your foot out of it. How can it not, because now it takes less throttle to obtain a desired speed, plus it no longer lugs the engine at low RPM. A 4 cylinder engine needs RPM's to be efficient.
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Unread 09-09-2007, 07:24 AM   #53
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Quote:
Originally Posted by unibus
Still worth it to me for the improvements other than mileage.
That's the way that I feel about it, too, even if I had lost an mpg or so. My "time trials/hot rodding" tank still ended up with 24.3 actual, 25.1 on the EVIC, even that is closer than before.

In trying to relate this to "old school" technology of distributors and carburetors, an off line stumble or bog could sometimes be cured by advancing the timing (2/3 degrees was plenty), adjusting the idle speed and/or adjusting the power valve. That relates to the recalibration of the Powertrain Control Module (GPEC) on all models.

There is no "old school" related to an electronic CVT so this is speculation: it reprograms the Transmission Control Module (TCM)to allow it to move to the lowest position possible (the original didn't quite put the variators in that position?) and/or it changes the other shift positions/ratios.

It could be that the reason it "appears" to have lost some power on the upper end is that it's now getting full advance on the timing sooner where before that full advance didn't kick in until the RPM's were higher giving you a feel of an additional kick in the pants.

There are two different Labor Codes for this TSB. One is for recalibrating the Powertrain Control Module (GPEC) without changing the CVT's Transmission Control Module (TCM) and the other Labor Code is for reprogramming both. This covers BOTH the CVT and the 5 Speed.

For me this is the most cost affective performance improvement that anybody can do with a build date of 4/21/07 or earlier! It's FREE .
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Unread 09-09-2007, 07:47 AM   #54
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Quote:
Originally Posted by Jason31
It will help on the highway as well. It does not require as much pedal travel to pass another vehicle. If you want more top end power, slap on the K&N Aircharger, I feel it helped quite a bit on top end. (and well it should!)

This design, by nature, WILL increase MPG if you keep your foot out of it. How can it not, because now it takes less throttle to obtain a desired speed, plus it no longer lugs the engine at low RPM. A 4 cylinder engine needs RPM's to be efficient.
I agree with Jason on these points. 4 cyl "tuner" engines run off of gearing and RPM. For more top end you need to change how well the engine breaths with a Cold Air Charger/Intake and a better exhaust including a header, if available. (Mud flowing the head and bigger valves could help, too, but that's another story )
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Unread 09-10-2007, 05:23 PM   #55
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to a jeep dealer here and he told me that there are no warnings (service bulletin) of that TSB here in Argentina.

i think, that there are not, because most of the warnings are for heacy problems, and not this kind of problems.

by the side, the dealer told me he can plug the starscan to the car and check if everything is ok, do you know the software version of the gearbox that is upgraded or somehting so i can check with him?

thanks.
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Unread 09-10-2007, 06:04 PM   #56
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Quote:
Originally Posted by pszemia
to a jeep dealer here and he told me that there are no warnings (service bulletin) of that TSB here in Argentina.

i think, that there are not, because most of the warnings are for heavy problems, and not this kind of problems.

by the side, the dealer told me he can plug the starscan to the car and check if everything is ok, do you know the software version of the gearbox that is upgraded or something so i can check with him?

thanks.
Are you able to print out the TSB and take in to him? It sounds like you may have found somebody willing to help you down there. He may say that it's worth looking at if he read the TSB.

It looks like the ECM must be of a certain level before you can do the TCM. All I see in the TSB is to "compare" the part numbers on the screen in step 7 to that of step 6e. No call out for what it should be other than the numbers on the "StarSCAN" tool.

Just a note: I recall in the early days of the Dodge Caliber (our cousin) that there were articles stating that the EU models would get different programming than the N. American versions. I don't know if this is true of all exports or not. If it is true then the code that he gets on his StarSCAN won't match and if he does a down load to program yours, you would then be running the same as the N. American Jeeps. Is this better or worse than what you have now? I don't know the answer to that.
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Unread 09-10-2007, 09:57 PM   #57
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mm i think i have EU version here, because as merlin sayd, its for export, but i dont know what about the changes of the software for this gerabox.

i think it will be bether to research wich one is better
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Unread 03-11-2008, 09:23 PM   #58
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Crap...I have spent hours googling for info on the stalling and overall bad acceleration from a stop on my Caliber SXT.

Then I find a link about the TSB's that takes me back to my beloved Jeepforum.com, where I spend 90% of my online time at already, and you guys have exactly the answers I was looking for.

Now I get to take my 1 year old car that stalls and I am afraid to drive my family around in, and take it BACK to the dealer that implied I was either nuts or incompetent, because their super-qualified techs couldn't recreate the problem in the 2 miles they drove it, and shove the applicable TSB's under their noses.

Thanks again JF!

I am rapidly running out of reasons why I should ever look at other websites.
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Unread 03-12-2008, 04:10 AM   #59
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Here's the link to the full list of PM and MK TSB's. It's the first place that I check for "new" problems. Since I've posted this link quite a few times I'm also putting it up in the "sticky" with MK's Off-Road and other links.

http://www.caliberforums.com/forums/...light=bulletin

Ahh, welcome back? J/K
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Unread 03-13-2008, 08:38 PM   #60
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Wow been awhile since I've hung out here.

To anyone that is still on the fence about doing this, make sure you get this done. I was afraid to drive my Compass sometimes because of the low-end stumble it had. I can safely say that I have no longer experienced this issue since, and its been many months since I had it done.
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