Odometer rollback issue

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Aug 19, 2013 | 10:30 PM

93sc

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Odometer rollback issue

So I have a 95 F-250 w/ a 460. I have an issue with the odometer rolling back roughly 1.0 miles after I turn the key on after driving. It doesnt happen all the time, it doesnt depend on the length of the previous trip, matter of fact I havnt found anything consistant about it. Just so I'm clear, I will park the truck and look at the odometer which will read 180265.4 (for example), I turn the truck off, then turn the key back to the on position at which point the odometer will now read 180264.4. Thats an example from 2 days ago. Oh yea, digital odometer. However, sometimes it just reads the same mileage. This is something I havn't seen before, so I'm not sure what is going on. I just happened to look the other day when I was trying to figure out my mileage. And while it's a 460 I expected better than 4.5mpg. If anyone has an idea, I would really appreciate it.

Aug 20, 2013 | 06:34 AM

rla2005

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Joined: Oct 2005

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From: Kentucky

The PSOM attached to the back of the speedometer stores the odometer reading. Pull it out and inspect for signs of leaking capacitors. The EPROM could also be bad.

Aug 20, 2013 | 06:38 AM

dixie460

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Joined: Nov 2011

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From: SW Florida

Yeah, the Programmable Speedometer/Odometer Module is the only thing that stores the mileage. If it ain't working, you can pull it out and see if it's repairable. If not, then you can get another from a junkyard but unfortunately you won't be able to store your current mileage. If you can get one with lower mileage than you currently have on your truck, you can set it up on a bench and feed it a signal until it reads the same as your current one, then install it and go.

Aug 20, 2013 | 07:28 AM

Jarryd

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Joined: Mar 2013

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Just keep turning the key on till the truck has 30k on the clock and pawn it off for profit.

Not serious.

Aug 21, 2013 | 01:59 AM

93sc

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Thanks guys. Sounds like its time to hit the junkyard.

Aug 21, 2013 | 08:52 AM

Eddiec1564

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Joined: Mar 2007

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From: Arcadia, Fla

The EXACT thing happened to my 95 E350 bus PSOM!! It is the PSOM malfunctioning and its time to replace it. At least you was loosing a mile, mine was not saving milage when I turn off the truck, but would save mileage like every 9 to 12 miles...... It took me a while to figure that one out. I dropped from 8.5mpg to like 1 or 2mpg due to that malfunction...

Here's some threads that are about the PSOM:

https://www.ford-trucks.com/forums/1...r-display.html

https://www.ford-trucks.com/forums/1...splay-fix.html