e40d woes... - PowerStrokeNation : Ford Powerstroke Diesel Forum
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post #1 of 6 (permalink) Old 12-09-2014, 02:26 AM Thread Starter
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e40d woes...

Hopin the psd gurus cud help me fig out a trans issue. more and more often as soon as i drive my truck the o/d light flashes and trans goes in failsafe. very hard shift and erratic /c lockup. ive read tons of forums with similar issues. weird thing is that within 15 mins of driving the light goes off and trans function returns to normal. Only code is po500. also when it happens the speedo is working fine. abs light doesnt come on. only od light flashes.im having trouble diagnosing this prob cause it only last a few mins. seems like it only does this when it has rainef the day prior. i only use the truck to haul rq usually around 8k lbs. the hard shifting i kno is failsafe but its harsh enough to brak somthing i think. Jus wondering if anybody has seen this prob like mine bein only at first drive.

any input is appreciated
i was planning on reading data on my scanner with it today an naturely it didmt do it. Im sure it will tho next time it rains
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post #2 of 6 (permalink) Old 12-09-2014, 10:01 PM
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Re: e40d woes...

The code means there is a problem with the speedo. Have you tried removing the VSS from the rear axle and cleaning or replacing it?

Since it is doing it only when it rains, at least that's what I think I've read, then it is likely that you have a wiring problem. It could be a damaged wire, or corrosion in a connector, or....

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post #3 of 6 (permalink) Old 12-11-2014, 12:52 AM Thread Starter
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Re: e40d woes...

Yes i tried the sensor itself. replaced it. i fig it wouldn't do any good since the speedo works. i drove it today an its done fine. the speedo does seem to flutter a tad. i mean like 2 mph max. is that enough to cause the issue? I gues not or it would've thrown the code. my guess is connection at pcm or firewall. gota get it to do it more to kno i guess
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post #4 of 6 (permalink) Old 01-25-2017, 03:54 PM Thread Starter
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Re: e40d woes...

been a while, the problem persisted and got worse. I mean, every time I drove it.. Also it has taken longer and longer to go back to normal. I found a used speedo/cluster and installed it and BAM!, fixed it. been on that cluster for a few months to confirm. Only prob now is this cluster does have a bouncy speedo, but the trans still works flawless and no more p0500 code. Guess next will be a "speedometer repair" lol. I kno its been a while but maybe this post will help somebody--
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post #5 of 6 (permalink) Old 01-25-2017, 05:32 PM
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Re: e40d woes...

interesting! Thanks for sharing. I deal with that P0500 alot lately it seems
it can also be RFI noise in the speed sensor wires, this is why the factory VSS wires are twisted together and in some areas shielded.
That was a fun one to troubleshoot.....new parts everywhere, correct vss readings per mile...turned out to be RFI noise from fuel pump...when I wired the custom V8 Ranger I did not twist the two VSS wires together, now I know better!

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post #6 of 6 (permalink) Old 01-25-2017, 09:09 PM Thread Starter
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Re: e40d woes...

after going thru this about 2years, i realized its probably more of a temperature issue than rain. it seems as tho last summer it would only do the problems when it was a cool eve or real early. anyway twisting wires and sheilding make alot of sense. esp for rfi interferance.
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