TSB #: 21-013-07

DATE: September 15, 2007

MODELS: 2006 - 2007 (WK and WH) Grand Cherokee SRT-8

SUBJECT: FLASH: Harsh 1-2 Shift Or 2-3 Shift

OVERVIEW: This bulletin involves selectively erasing and reprogramming the Final Drive Control Module (FDCM) with new software.

SYMPTOM/CONDITION: A bump or a harsh shift is felt by the customer caused by the transfer case actuation. Customers describe this as either a harsh 1-2 shift or 2-3 shift. The transfer case clutch actuates at 20.5 mph for approximately 750 ms after each key cycle as directed via FDCM software to re-learn the clutch starting position. This can generate a torque pulse in the driveline under light to medium throttle conditions that can be construed as a transmission shift event.

PDF file of bulletin: TSB 21-013-07 (http://www.wkjeeps.com/tsb/tsb_wk_2101307.pdf)

Thanks for posting.

Resume,
GREAT info.
However, the "bump" is not bothersome to me and I have learned to expect it.
The ONLY way I would ever let them do this to my JGC is if I bought a spare FDCM and had them flash it. Then I could go back to my non-flashed FDCM if I did not like the re-flash.
Bill

i have a 07 build date 06-07 and so far i havnt seen this trouble but i only have 600 miles on the jeep. thanks 4 the info.

Thanks for the news. I have an appointment on Thursday for the update and some other odds & ends. It's driving me crazy, so I will try the update.
I'll keep you posted on the change, if any.
Jimmy

i was hoping this was for the shift hesitation... may do it anyways

Is this the same as the transmission self check?

Thanks
Bob

I would imagine anyone picking up the Diablo does NOT need this?

Is this the same as the transmission self check?

Thanks
Bob
Sounds like it

Having this done tomorrow....as I get the "bump" between 2nd and 3rd.

On a side note: I don't think that my service dept likes that I know more about my Jeep than they do. You should've seen the service tech's face when I showed him the printed out TSB. I could tell he hadn't seen it yet...and he's probably thinking..."this guy is going to be a high maintenance customer" ahhahah :D

Ok...had it done today. Results: It did absolutely nothing.:mad: Still feel the bump between 2nd and 3rd.

Anyone else do this?

That sux...

how do you find the sale code ESF as stated in the TSB.

how do you find the sale code ESF as stated in the TSB.
All 6.1 engines are sales code "ESF".

I too am experiencing this, it sounds like a loud clunk under the car between 1 & 2. But with my experience at the local dealer, I don't want to take it in unless I know it will help. If anyone else does this, please post results.
Thanks