Power Hungry Performance Forum  

Go Back   Power Hungry Performance Forum > Ford Super Duty & Excursion > 1994½ to 1997 7.3L Power Stroke Diesel

1994½ to 1997 7.3L Power Stroke Diesel 7.3L Power Stroke Diesel equipped F-Series and F-Super Duty

Reply
 
Thread Tools Display Modes
  #1  
Old Wed, September 14th, 2011, 02:28 PM
Longshot270's Avatar
Longshot270 Longshot270 is offline
Forum Predator
 
Join Date: Jul 2009
Location: DFW, TX
Posts: 2,688
Longshot270 will become famous soon enough
Default OD off blinking

My dad's '97 PSD F250 has been having a transmission issue for a while now. Ever so often the OD off light will start blinking and the truck will start shifting much firmer. That is all that happens until he unhooks the batteries and clears the code. The code reader he bought for the expedition doesn't pull any codes off the truck. His friends at work are saying because it has two computers, the PCM and one other (I'm assuming they are referring to the FICM) and because of this his code reader can't pull codes. He talked to a guy at a transmission shop and they told him that his TC clutch is probably starting to wear out. They said when the TC does a full rotation that it will trigger a code and make the light blink. This seems logical but, as I said earlier, no codes are available to make sure. He told me the guys at autozone said they couldn't pull codes because apparently they use the same unit. Is this common enough to buy a new TC and start throwing expensive parts at it without knowing for sure? The truck is not even touching a dealership parking lot. He has also been looking around at prices of new TCs and because of the directions of his coworkers he thinks he can just change it out in his garage after removing a few bolts. I'm getting the feeling that regardless of what his coworkers say, this is no easy task that can be done with just a pump jack, a set of wrenches and a change of ATF.

Thanks in advance for any info.
__________________
Reply With Quote
  #2  
Old Wed, September 14th, 2011, 05:25 PM
cleatus12r's Avatar
cleatus12r cleatus12r is offline
F Your Yankee Blue Jeans
 
Join Date: Jan 2009
Location: Somewhere in Montana
Posts: 3,063
cleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to allcleatus12r is a name known to all
Default

Nope, one computer for the engine and transmission.

If the OD OFF light is flashing, then there is a transmission problem and likely a P1728 code which means slippage. In an effort to "save" the transmission, full line pressure is commanded and you get the harsh shifting you describe.

Time to figure out what the code is and go from there with data.

The problem with the 95-97 PSD trucks is that the PCM cannot differentiate between a torque converter clutch slip or a direct or overdrive clutch slip. The 99-up trucks have an input shaft speed sensor so they CAN.

You can throw parts at it all day long and still not fix it. I recommend actual diagnostics.
__________________
Tuning, flashing, burning chips, and repairing all aspects of 7.3L Powerstrokes.
SEVEN 7.3L-powered vehicles in the driveway. Two didn't come that way from the factory!
Reply With Quote
  #3  
Old Wed, September 14th, 2011, 08:57 PM
Longshot270's Avatar
Longshot270 Longshot270 is offline
Forum Predator
 
Join Date: Jul 2009
Location: DFW, TX
Posts: 2,688
Longshot270 will become famous soon enough
Default

Thanks, I emailed my mom and hopefully he'll listen.
__________________
Reply With Quote
  #4  
Old Tue, September 20th, 2011, 04:11 PM
rammertide07 rammertide07 is offline
God & Guns
 
Join Date: Dec 2010
Location: Rogersville, AL / Currently in Pollock, LA
Posts: 307
rammertide07 is on a distinguished road
Default

Generic code readers (like what autozone uses) will not pull Ford specific codes. Most transmission shops and some engine shops use something like the Snap-On or AutoEnginuity. These will pull the codes when the light is flashing.
__________________
01 F350 7.3 4x4 CC SRW/3.73/315-75-16/Aeroforce Interceptor/BD Thruster II/ Bellowed Up-Pipes/4" turbo back exhaust/CCV Mod/DIY 6637/FPR Shimmed to 65 PSI/TS chip reburned with PHP tunes (Stock, 40T WITH Whsiper tune, 80DD, 100R, 140Ex, 140SS)/Replaced and Cleaned EBPS & Tube 4-6-12/Zoodad mod/Recon smoked cab lights/MM Hubs/Cowl Hood/HPx
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -5. The time now is 11:30 AM.


All Contents Copyright 2008-2020, Power Hungry Performance