[Budsky]

My wagon with around 3500mi on it has started this very abrupt downshift/clunk/jerk when letting off throttle and slowing.
Never had it happen until shortly after a full throttle application- which also downshifted hard.

Reading up on it the downshift clunk is very common in other applications of the 6R80.

The thing that usually fixes it is a Keep Alive Memory (KAM) clear.
Afterwards the transmission relearns it's behaviour and that usually fixes it.

Problem is no common reasonably priced scan tool can do that.

And -No- pulling the battery connection will NOT clear the KAM.

I really hate to go to the dealer for this clear procedure..I'm in the middle of getting the van reconfigured and loaded out for a 30 day+ 10,000 mi + trip in a few weeks.

I'm not opposed to spending up to say $300 for a scan tool that will clear the KAM but many of the vendors of better scan tools are evasive or unknowledgeable about their product. Yes I would spend $300+- to avoid a dealer touching my van:|


Anyone ever dealt with this?

 

[alarmist]

I think it works if you leave the battery disconnected for long enough, or short the + and - leads while it's disconnected. Never tried though, and I suspect you've done some research on this. I've read the important part is to re-adapt the shift points after by following a specific driving procedure.

 

[Budsky]

According to the people who have tried it never loses the KAM unless it is forcefully reset.
I did try the battery disconnect and it did not work.

 

[Tim]

My 2017 250 started doing that about a month ago. Around 10,000 miles and 8 months old. I'm just wondering what if any kind of damage or wear on drive line related parts it is doing. And I feel the same way about the dealer since I went in to get tires rotated and they left 70 in the front and 50 in the rear tires.

 

[DG 154 AA]

I believe ForScan will do that.

http://www.forscan.org/forum/viewtopic.php?f=5&t=1602

 

[Yaldor]

For Ford transit 2015 how do I use the forscan product ? What OBD tool is needed to connect ? Can someone points me to the basics as I am new to this ?

TIA.

 

[Budsky]

Update- I noticed the other day I do NOT get the downshift "clunk" in Tow/Haul mode- which seems to indicate to me that it is not an internal transmission mechanical fault- something in learned parameters most likely.

 

[Tim]

I did the KAM reset thing at the dealer 2,days ago and the downshift clunk when rolling up to a stop seems to be gone. They said to drive it for 100 miles so it relearns my driving.

 

[Budsky]

How much trouble was it? Were they able to do it fairly quickly and did they do a PCM update as well?
I'm thinking it should be a very quick fix....but you know how backed up some dealers are.
As much as I hate to I guess I'll have to go to a dealer....

 

[Tim]

Under warranty, has 12k miles. We waited for it, probably hour and half. Not sure about pcm. Took about a week to get appointment as their trans guy is backed up.

 

[Budsky]

Thanks...I may be out of time- leaving next Friday for a trip to Canada and Alaska.
Guess I'll call and see.
The clunk is only an issue in stop and go driving, now that I discovered the T/H mode stops it I at least have a workaround.

 

[Budsky]

My OBD adapter is due to arrive today- the one I use on the Torque app will not work with Forscan.
I stopped by a local dealer the other day to see about getting them to look at it. What an unpleasant experience.
They make appointments - but their idea of an appointment is drop it off in the morning and they get to it when they get to it. Even if they know you are waiting on it.


Learned a little more- there are apparently 2 things to do- clear the KAM and then reset/clear/erase the Transmission Adaptive Tables.

Fingers crossed I can make this work...hate going to a dealer.

 

[Budsky]

YES!!

My adapter came- plugged it into the vehicle- ran the ForScan program, found the RESET LEARNED TRANSMISSION PARAMETERS (or something like that).

Went for a drive-

And my 5-4 downshift clunk is GONE!

I am ecstatic I spent $30 for an adapter and spent a little time the last few days studying what I could find on ForScan >
and I DIDN'T HAVE TO GO TO A DEALER!

A BIG thank you to some very generous genius's that wrote ForScan and make it available for FREE!

Here is the adapter I bought- apparently there are many that don't work right on ForScan>
https://smile.amazon.com/gp/product/B01F0GVBWY/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

 

[EddieZ]

Great news. This thread and that solution may be a great reference in the future.

 

[ShadeTreeMech]

Following up on this ...

Do you think using FORScan to invoke relearning the Transmission Adaptive Tables could be useful for someone buying a used Transit or to adjust to a new "everyday driving" environment?

 

[alarmist]

If it ain't broke don't fix it.

 

[Budsky]

Do you think using FORScan to invoke relearning the Transmission Adaptive Tables could be useful for someone buying a used Transit or to adjust to a new "everyday driving" environment?

If it seems to be operating normally I wouldn't force a relearn. It could always go wrong and then you really have a problem.

 

[ShadeTreeMech]

If it ain't broke don't fix it.

That's about how I see re-calibrating the speedometer for the larger tires. Nice to have the MPG on the trip 'puter almost dead on as it is. Next time I hook it up I'm also going to look for the "Ignition Counter (IGN_CTR)" referred to in Ford's GSB G0000095 .

Thanks for sharing your experience and your reply.

 

[Budsky]

Interesting how Ford uses that "Ignition Counter" to see if there has been any "unauthorized" PCM calibrations.
Would be interesting to see if that counter is cleared from something as minor as the clearing of the Trans Adaptive Tables.
If it is- then I guess we need to cycle the key a ton of times to make it look like it never happened.....

Speaking of speedometer cal- I've noticed both of my Transits speedometers show that I'm going a little slower than is actual- verified with GPS.
Used to be every vehicle I've ever checked had a built in 1-2 MPH+ error the OTHER way, IOW you were going a little slower than it said.

 

[ShadeTreeMech]

'puter modules

What I read on the Ignition Counter and warranty issues suggests it's not "valid" for denying a claim, but "some" Ford dealers will use it anyway - despite the Magnuson-Moss Warranty Act.

Sometimes I think these 'puter modules are crazier than I am. I've got a '17 Tacoma that I have to add 5 miles to the odometer for every two hundred miles (checked with two different "marine" Garmins), but it's real time MPG and the digital speedo are very accurate. Seems +/- 2% is considered to be within specs. The '15 Transit was slow about 1 MPH at 60 with stock tires, but the odometer was pretty close (did seem to be some minor rounding error between the trip mileage and the main Odometer).

I did finally come across Donutman's post on editing the CC. I'll have to go back in and look several things over before Mercury goes into retrograde again next month.