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Discussion Starter #1
well i think i posted about this a couple months ago and i didnt have to many problems after i posted. but now it keeps happening. well i have a 1997 f250 with the e4od trans. the previous owner told me that the tranny was rebuilt stronger. but he had no reciepts to prove it. but i can tell you it has an ats purple converter in it. but thats all i know. well this is whats going on, usually what starts the problem is I will be cruzing down the highway and at any givin speed I can feel my converter unlock for about four seconds and then lock back in. then my o/d light starts flashing. which will shut off about 2 to 5 miles down the road. Then say I get off the highway after this happens and I come to a complete stop there is two things that will happen. First one is, I go to take off and it will shift into second at about 8mph then into third with the converter locking at about 18mph. So the truck has no power cause it is in such a high gear for how slow I am going. The second thing is it will try to shift into second but it will miss the gear and just rev like I'm in nutraul. so I have to pull it over and I will run the shifter through the gears. Go to take off again and it will hold first gear for a long time then just bang into second feeling like the whole trans just feel out . but it will shift fine after that. this hasen't happened for a while. usually it shifts really early. but i can come to a stop shut the truck off wait 5 seconds start it up and it will be fine. i did get my codes checked and there was only two codes in it. one was for a vehicle speed sensor, and the other one was for the crank shaft position sensor. i replaced the vehicle speed sensor but that did not help. sorry for the long post but i want to give as much info. i can to get this figured out. thanks for your guys help.
 

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Former Ford Trans Engr.
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You need to fix what's wrong with the vehicle speed sensor and the crankshaft position sensor. If the sensors are not sending the right info to the computer it is not going to shift right.

The codes do not necessarily mean the sensors are bad. It could be the wiring to the sensors.
 

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Fixing Broken Stuff
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Sound like the PSOM, which would mean you need a new speedometer. The PCM gets its speed signal from the PSOM in the speedometer head. You can read the MPH on a scanner, I think you will find it way off when it acts up.
 

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Discussion Starter #4
i was wonder if it wasn't a wring issue. but it acted up again today and i got the same vss fault and the other one was a p0236 turbo boost sensor A. so i am going to trac wires as far as i can and see if i see any problems. also do ou think there could be a problem with the harness going to the trans? thanks for the help guys.
 

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Former Ford Trans Engr.
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No, it isn't a problem with the harness going to the trans. Tracing the wires is fun, but doesn't help. You need to electrically check the wires, not visually check them.
 

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Does the speedometer read normally?

AFAIK, there is no crank position sensor. What are the actual codes (not the descriptions) you're getting?
 

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Former Ford Trans Engr.
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There is a crank position sensor on Powerstroke engines.
 

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Discussion Starter #8
what do you mean by electrically checking the wires? ohm's testing them? yes there is a crank sensor cause i have replaced once already. and the speedo reads fine with no problems. again thanks for the help.
 

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Discussion Starter #9
also toolmangary what is the psom?
 

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Former Ford Trans Engr.
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what do you mean by electrically checking the wires? ohm's testing them?
Checking each wire for continuity, short to ground, and short to power.
 

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Discussion Starter #11
alright i will be doing this this weekend and will let you know my findings. thatnk for the help.
 
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