Possible TC issues??? - Ford Powerstroke Diesel Forum
Please Visit our Site Sponsors
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
LinkBack Thread Tools Display Modes
Old 04-25-2012, 05:12 AM

Join Date: Jun 2011
Posts: 88
Thanks: 1
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Possible TC issues???

Been having a couple of issue for about a month now and one seems to be getting worse. First, when coasting from highway speeds and at 40 MPH when the TC unlocks my engine's RPMs fluctuate down then back up and then levels out at idle. Seems to be not a whole lot of movement, but is definitely noticeable to the ear. I would say it first drops down to about 600rpm, bounces back up to 850'ish and then levels out at the usual 750. Now today I noticed it kind of spudder a little when it happened (twice).

I do not have a blinking OD light, but there is a SES that comes on when kind of lugging the truck like when you first take off from a stop or cruising at lower RPMs. I have had the codes read and have an IDM code that is more than likely due to a chaffed wire somewhere.

I just dropped the pan and changed the filter about 300 miles ago but this was going on before this.

The second issue is when accelerating up to highway speeds it seems like the TC locks up at the same time as the transmission is shifting at about 40mph resulting in an odd feeling shift. I have PHP tunes on as 98% of the time ride around in the 80DD tune. I can vary my pedal when accelerating and get the 2 events to happens separately and everything feels fine, but if accelerating and not thinking about it is when I feel it most. Thank you in advance for any help given.
Reply With Quote Quick reply to this message
Sponsored Links
Old 04-25-2012, 06:50 AM

Join Date: Jun 2011
Posts: 88
Thanks: 1
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
The more I sit back and think about it, the more inclined I am to think this may be related to my SES vs. the transmission. A sudden drop in RPMs (like the TC unlocking) causes a change in voltage (or rather the fire event signal) from the IDM and if I do in fact have a short or bad IDM the engine may stumble a bit. I am just think out loud here and may still have a TC issue, but guess it's time to break out the multi-meter and start doing pin-out checks on the IDM to UVCHs. Still welcome to any input as well especially if anyone else has had the engine symptoms mine is having. Thanks!
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 11:45 AM.

Powered by vBulletin® Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.