Transmission quirks

artickid · **Posted:** Sat Mar 22, 2008 3:52 pm

When cruising at highway seeds with the cruise set at around 62 it has downshifted violently for no reason. After the schock of this I can resume my normal cruising speed and it seems to funciton normally. There are no codes per the SGII other than the ORM code. This has happened 4 times in the past month. I currently have 50k on the clock with all of the recalls completed. Has anyone else experienced this or have any inshight into what is going on??

Thanks

Uffe · **Posted:** Sat Mar 22, 2008 4:34 pm

Others have reported that the SGII makes the transmission shift unexpectedly at various speeds when connected.

Noone has AFAIK come up with any solution to the problem - except not to use the SGII.

Sorry.

crd liberty · **Posted:** Sat Mar 22, 2008 4:41 pm

artickid wrote:

When cruising at highway seeds with the cruise set at around 62 it has downshifted violently for no reason. After the schock of this I can resume my normal cruising speed and it seems to funciton normally. There are no codes per the SGII other than the ORM code. This has happened 4 times in the past month. I currently have 50k on the clock with all of the recalls completed. Has anyone else experienced this or have any inshight into what is going on??

Thanks

Hi
In my CRD 62 is right on the borderline of shifts. Mine shifts last drive at 63 and the slighest wind or hill will make it want to shift back down.
Maybe trying to set to cruise at 65 and see how that goes??
Steve

Uffe · **Posted:** Sat Mar 22, 2008 6:38 pm

crd liberty wrote:

Hi
In my CRD 62 is right on the borderline of shifts. Mine shifts last drive at 63 and the slighest wind or hill will make it want to shift back down.
Maybe trying to set to cruise at 65 and see how that goes??
Steve

Sounds strange, there is a hysteresis on gear shifts. If I get to 2nd OD gear I can back off from 63 to 56 with no downshift, and I have to exceed at least 62 to get back to 2nd OD.

Joe Romas · **Posted:** Sat Mar 22, 2008 6:48 pm

He's atalking violent shift here :lol:

Mine hits top gear at 62 or 3 and will remain there untill about 60 or maybe 59.

But there has been SEVERAL SEVERAL instances of this happening with a scangauge attatched :shock:

The bata bus on the CRD is a kludged mess

Pablo · **Joined:** Thu Feb 02, 2006 10:06 pm **Posts:** 1201

The violent shift is the torque converter falling out of lockup because the TCM locked up and rebooted itself. Don't use the Sanguage while driving if you have this issue. It is in a previous thread somewhere...

Jim Friese · **Posted:** Sun Mar 23, 2008 1:15 pm

Pablo is right about the scan gage II I had it happen to me and its not fun. Do not use the Scan Gage II . I hit the 5th gear at 65 MPH.

Jim

artickid · **Posted:** Mon Mar 24, 2008 9:42 pm

Thanks for your input, my first thought was that the SGII may have been causing this but wanted to know what others thought. I now feel better about my 3,000 mile trip coming up.Thanks

nix · **Posted:** Tue Mar 25, 2008 12:04 pm

The SGII/violent transmission shift thing hasn't been proven yet. But it seems likely. I have experienced this violent gear change several times. I've had my SGII plugged in permanently for the last 10+ months of driving.

danoid · **Posted:** Wed Mar 26, 2008 9:34 am

To me it sounds like your transmission controller either 'fell off the bus' or lost power and threw the transmission into limp mode (3rd gear - torque converter unlocked). If it's only happening when the Scangauge is connected, then don't connect it.

fastRob · **Posted:** Sat Mar 29, 2008 5:37 pm

When I went in for recalls Jeep did a F31, Reprogram TCM for Aftermarket Scan Tool, it was dated August 14, 2006.
Has this been done on your machines?
Or is this the cause of problems?
R

Joe Romas · **Posted:** Sat Mar 29, 2008 10:08 pm

fastRob wrote:

When I went in for recalls Jeep did a F31, Reprogram TCM for Aftermarket Scan Tool, it was dated August 14, 2006.
Has this been done on your machines?
Or is this the cause of problems?
R

Rob.

F31 was needed because of a earlier "silent" flash, kind of a "pre F37, to improve the torque converter operation. It had the added feature of making third party OBDII scan tools not work :cry:

That was against EPA requirements :lol:

I got my BCM flashed in June 06 and that's when I unknowingly got it

So without F31, if needed, your scan tool won't work. The real problem is the way the whole data bus is kludged together on our CRD's :roll:

bluefish · **Posted:** Sun Mar 30, 2008 10:39 am

I had the same thing happen to me. At first I thought that the Scan gage was the cause. Then it happen with out it plugge in. I was going 55 plus it just down shifed so hard it cherped the tires. Took it to the shop they claim could not dulp. but I have not seen to do it again. I thought I read some where in the form that they had a fix for this in one of the Tech bulitens.

chrispitude · **Posted:** Sun Mar 30, 2008 11:55 am

bluefish wrote:

I had the same thing happen to me. At first I thought that the Scan gage was the cause. Then it happen with out it plugge in. I was going 55 plus it just down shifed so hard it cherped the tires. Took it to the shop they claim could not dulp. but I have not seen to do it again. I thought I read some where in the form that they had a fix for this in one of the Tech bulitens.

This reminds me. I had this happen to me once while towing my 5000lb trailer, before I even bought my SGII. It was very violent, since the trailer basically wanted to push forward into the KJ as it was trying to downshift at highway speed. My wife and I both thought we hit something, or that something snapped or broke on the CRD or trailer. It shook everything so bad, the trailer connector dislodged and I lost my electric brakes. I was able to pull off the side of the highway and inspect everything, and nothing was amiss. We got back on the highway and the rest of the trip was uneventful.

- Chris

Transmission quirks

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