Is my TCM flashed to F37?

UFO · **Posted:** Tue Dec 22, 2009 12:52 pm

I hope this is not counterproductive or redundant, but the search feature on this new forum software is not returning anything related to F37. I know I've read of various tests for telling the old pre-F37 flash from the new, but some of the information seems conflicted. I just want to verify that my '05 CRD is indeed neutered, as I bought it used from a Jeep dealer in '07 who said all the recalls and such were done.

So what are the confirmations? Is there documentation online using the VIN? Can one tell using the top shift points? My impression is the final shift point of the F37 is just over 60mph indicated, but my Jeep seems to hit that final shift around 57mph indicated...

I'm hoping we can summarize the information and/or links in this thread so everyone can know where they stand...and those that have not yet been neutered can brag about it, and hopefully be good sources for the code so eventually all may reflash to pre-F37 once the TCM is hacked.

stoutdog · **Posted:** Tue Dec 22, 2009 1:46 pm

Shifting ~58mph = non-F37
Shifting ~61mph = F37

Check with a GPS, just to be sure.

linewarbr · **Posted:** Tue Dec 22, 2009 1:48 pm

This is the website for checking your VIN against the Jeep database:
http://www.jeep.com/en/owners/

It is my understanding that an F37'ed CRD will shift into 5th lockup at about 64 mph via the uncorrected speedo. On mine, it shifts at 61 mph real-time via GPS. (which is 64 on the speedo) IIRC, a non-F37'ed CRD shifts into 5th lockup at 57-59 mph.

there is a way to check the sticker on the ECU/ TCM, but I never really understood it and didn't try since I knew mine had been neutered.

UFO · **Posted:** Tue Dec 22, 2009 5:02 pm

stoutdog wrote:

Shifting ~58mph = non-F37
Shifting ~61mph = F37

Check with a GPS, just to be sure.

That's with the factory size tire I'm sure. Is the factory speedo reading fairly consistent vehicle to vehicle?

stoutdog · **Posted:** Tue Dec 22, 2009 6:12 pm

UFO wrote:

stoutdog wrote:

Shifting ~58mph = non-F37
Shifting ~61mph = F37

Check with a GPS, just to be sure.

That's with the factory size tire I'm sure. Is the factory speedo reading fairly consistent vehicle to vehicle?

Seems to be. That's why I recommend using a GPS to be sure.

UFO · **Posted:** Tue Dec 22, 2009 6:42 pm

stoutdog wrote:

UFO wrote:

stoutdog wrote:

Shifting ~58mph = non-F37
Shifting ~61mph = F37

Check with a GPS, just to be sure.

That's with the factory size tire I'm sure. Is the factory speedo reading fairly consistent vehicle to vehicle?

Seems to be. That's why I recommend using a GPS to be sure.

My actual speed is higher with my 215/85/16s. The odometer correction is -4.25%, so I've got to use the indicated speed from the speedo. The Jeep site says nothing is outstanding on my vehicle, but the shifting definitely seems like pre-F37.

linewarbr · **Posted:** Tue Dec 22, 2009 6:47 pm

x2 on the GPS. The main reason I bought mine is not because I have a poor sense of direction, but for the speedometer function. I drive too fast to not know for sure how fast I am going.

I'm running 245/70/16's on mine. Not much of a difference compared to 215/85/16's, but I don't think you'd get 3 or 4 mph difference.

CRD Joe · **Posted:** Wed Dec 23, 2009 12:45 pm

stoutdog wrote:

Shifting ~58mph = non-F37
Shifting ~61mph = F37

Check with a GPS, just to be sure.

darn! Id way rather my truck shift at 58mph than the bloody 61/62mph that it does... BUGGER! :JEEPIN:

mikey1273 · **Posted:** Wed Dec 23, 2009 1:07 pm

mine shifts into 5th at about 62 MPH also. I used the site linewrblr posted to check mine for recalls as well, mine has nothing known left undone. I am often driving longer on roads where you can't go over say 50-55 and wish it would lock in to 5th at that speed sometimes for cruising to save fuel.

Joe Romas · **Posted:** Wed Dec 23, 2009 3:39 pm

Two things.

One is regardless what tires you have the speedometer in relation to shift points should remain the same independent of true speed. So it's eather late 50's or early sisties :lol:

Second, for the first two weeks of ownership my 06 was unflashed. I didn't like it because of the droning it made shifting that low. It was very evident and noisey :roll:

But I do wish it didn't junp to around 2400 rpms with just a gentle touch of the go peddal

UFO · **Posted:** Fri Jan 01, 2010 1:58 am

I'm still confused. Here are the shift points on my CRD with OD on.

1-2 10mph
2-3 20mph
3-4 35mph
4-5 46mph
lockup 58mph

Is the only distinguishing feature of F37 the shift points? My CRD is supposedly up to date according the Jeep database, but it acts like it's not F37?

stoutdog · **Posted:** Fri Jan 01, 2010 2:51 am

UFO wrote:

I'm still confused. Here are the shift points on my CRD with OD on.

1-2 10mph
2-3 20mph
3-4 35mph
4-5 46mph
lockup 58mph

Is the only distinguishing feature of F37 the shift points? My CRD is supposedly up to date according the Jeep database, but it acts like it's not F37?

My dad's CRD, also an '05, shifts at those exact same speeds. The Jeep database also indicates that he has had all the recalls done... Best we can guess is that his TCM wasn't flashed, but the TC was replaced. Freaking miracle :BINGO:

Rich · **Posted:** Fri Jan 01, 2010 6:54 pm

how does the CRD act when lockup engages?

My 05 sounds like it has the same shift points as above.

CATCRD · **Posted:** Fri Jan 01, 2010 8:12 pm

Rich wrote:

how does the CRD act when lockup engages?

My 05 sounds like it has the same shift points as above.

The drop in rpm is really the only thing you notice at lockup.

The shifts are actually

1-2 - 10mph
2-3 - 20mph
3-4 - 35mph
still 4th with torque converter lockup - ~50mph
4-5 with torque converter lockup - 58/61mph depending on flash

UFO · **Posted:** Sun Jan 03, 2010 1:06 am

Yes, I rechecked. The lockup is at about 50, and the 4-5 shift at 58.

Is my TCM flashed to F37?

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