Limp mode?
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Mountain Pass
Joined: Sep 2017
Posts: 200
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Limp mode?
I've got a 2002 f350 dually with the 7.3 powerstroke I believe is stuck in limp mode or something worse. Yesterday the truck was driving just fine untill I shut it off for about 20 minutes. Once I start the truck it starts shaking like a bat out of hell and the overdrive off like is flashing. I put it in drive and it starts shaking even worse and almost dies so I shut it back off and call my brother to come help me tow it back home. We get all the way home and I start the truck back up again, started and drove like nothing happened.
I know that usually when the OD light is flashing it usually means to clean the sensor attached to the back axle but I did that right before all the happened. My guess is either the fuel pump went to crap or one of the harnesses to the injectors are really loose. I just would like to know for sure before I take the value covers off. Any help on this would really be appreciated especially since it's my daily driver.
I know that usually when the OD light is flashing it usually means to clean the sensor attached to the back axle but I did that right before all the happened. My guess is either the fuel pump went to crap or one of the harnesses to the injectors are really loose. I just would like to know for sure before I take the value covers off. Any help on this would really be appreciated especially since it's my daily driver.
Tuned
Joined: Jan 2015
Posts: 342
Likes: 38
From: Espanola New Mexico
whenever something "magically" fixes it's self I start looking at electrical connections and rub points. rough running shaking, I would look at 42 pin near the driver side valve cover rubbing on the bottom.
O/D flashing I don't think would cause rough running, though I could be wrong and it would not be the first time today.
O/D flashing I don't think would cause rough running, though I could be wrong and it would not be the first time today.
Fleet Mechanic
Joined: Sep 2011
Posts: 1,613
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From: Albuquerque
https://www.ford-trucks.com/forums/1...-7-3l-psd.html
A great place to start for some pointers to get you looking in the right direction!
A great place to start for some pointers to get you looking in the right direction!
Tuned
Joined: Jun 2007
Posts: 431
Likes: 66
Think about the obvious first. Have you done the Hutch/Harpoon mod? Was your fuel about 1/4 tank? Check the major connections. Also check out the Texh folders at the top of the forum, an abundance of great info to get you headed in the right direction.
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Mountain Pass
Joined: Sep 2017
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Never done a Hutch/Harpoon mod I have no clue if it's been done to the truck. The fuel is about 3/4 tank when it started happening.
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Mountain Pass
Joined: Sep 2017
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Started the truck this morning and everything is still fine I do live on a dirt road and I wouldn't doubt the washboard isn't slowly rattling connections apart. I did hear the fuel pump priming as well. Once I get home I will check all connectors and fuses.
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Logistics Pro
Joined: May 2017
Posts: 4,666
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From: Muskogee, Ok
I could also be wrong, which I wouldn't doubt when it comes to those of you with those mysterious autos, but I thought the O/D light was an indication of transmission codes, and that the ABS light was an indicator for an issue with the rear ABS speed sensor on the differential?
If so that makes me think more along the lines of your torque converter not unlocking and causing the shakes
If so that makes me think more along the lines of your torque converter not unlocking and causing the shakes
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Fleet Mechanic
Joined: Nov 2009
Posts: 1,378
Likes: 190
From: Cambs, England
The OD light flashing indicates a transmission problem & there will be a code/codes, tbh it sounds like you have a separate issue with the motor which may also have some codes, people think that the CEL illuminates when there are codes, but not generally unless they affect the emissions.
Our trucks don't have a limp mode on the motor AFAIK.
Our trucks don't have a limp mode on the motor AFAIK.
Laughing Gas
Joined: Jan 2017
Posts: 1,215
Likes: 94
Does your accelerator pedal work when this is happening? My truck used to have similar spells turned out to be a blown PCM. It would go into some kind of limp mode we’re pedal to the metal about 5 mph was all I would get. Probably due to the electrical problem than being programmed into the truck. From my understanding the PCM can generate its own version of codes however I’m not sure how to exactly access them.
Tuned
Joined: Jun 2007
Posts: 431
Likes: 66
Not too long ago I think I had a flashing O/D light along with the loss of power when using th go-pedal but it would idle just fine. I idled back to the house and started digging. Turned out to be a bare wire in the shifting arm down at the steering column. Repairing that wire resolved my problem.
It's a Van Gogh
Joined: Feb 2010
Posts: 7,795
Likes: 1,326
From: Elk Grove, CA
Getting the same feelz as Aubie, sounds like a chaffed wire in the steering column.
Here's the classic thread.
On edit: FWIW there is no limp mode on there trucks, too simple for that. When things break they run crappy.
Here's the classic thread.
On edit: FWIW there is no limp mode on there trucks, too simple for that. When things break they run crappy.
Tuned
Joined: Nov 2018
Posts: 292
Likes: 64
From: PA
Limp mode?
I do
remember reading in FM manual that the pcm is capable of performing the same action as a "limp mode" if certain sensors are not normal range.
I found it in the troubleshooting pages for specific issues.
I could go back and try to locate the references if I can refind them.
So, it might be possible, just don't have the references in front of me to share.
remember reading in FM manual that the pcm is capable of performing the same action as a "limp mode" if certain sensors are not normal range.
I found it in the troubleshooting pages for specific issues.
I could go back and try to locate the references if I can refind them.
So, it might be possible, just don't have the references in front of me to share.
Thread Starter
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Mountain Pass
Joined: Sep 2017
Posts: 200
Likes: 0
Does your accelerator pedal work when this is happening? My truck used to have similar spells turned out to be a blown PCM. It would go into some kind of limp mode we’re pedal to the metal about 5 mph was all I would get. Probably due to the electrical problem than being programmed into the truck. From my understanding the PCM can generate its own version of codes however I’m not sure how to exactly access them.
Thread Starter
|
Mountain Pass
Joined: Sep 2017
Posts: 200
Likes: 0
Not too long ago I think I had a flashing O/D light along with the loss of power when using th go-pedal but it would idle just fine. I idled back to the house and started digging. Turned out to be a bare wire in the shifting arm down at the steering column. Repairing that wire resolved my problem.