speedometer problems ad trans problems

[cowman79]

So I was driving home this morning at around 55 or 60 mph and all of the sudden the speedometer goes full scale. It held at around 90 mph and the mileage reading went blank until i started to slow down. Once i dropped to about 35 mph the speedometer came back along with the mileage reading. While the speedometer was on the blink my over drive button was flashing until I slowed down. Once I slowed down It was already into limp mode. I havent had time to pull the codes from the transmission computer. I was wondering if you guys had maybe seen anything like this before.

 

[direwulf23]

An E4OD,right? Well,the transmission must have the proper input from the speedo to work. If the speedo came back it's likely an electrical problem. Could be the speed sensor (VSS), fuses, or wires, of course.

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[cowman79]

Yes it is an e4od. The speed sensor is around a year old. I was hoping it is something simple like a speed sensor and not a wiring issue.

 

[direwulf23]

I would too, lol.
I'd always start with fuses, but, again, it magically fixed itself; so that seems very unlikely. Go from the easiest/cheapest to hardest/most expensive.

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[cowman79]

I have a spare speed sensor. The original wasnt bad when I replaced it. I might start there. It is hard to fix problems that dont stay broke.

 

[direwulf23]

Incredibly, or impossible, to fix ghost problems. That is almost always the case when I take my work truck to a mechanic. Lol

1994 Ford F250, 2wd, 7.3L IDI, NA, E4OD

 

[cowman79]

well it looks like the code was a problem with the speed sensor. I installed an old one that I think was good and cleared the codes. I am going to drive it tomorrow and see what happens. I am hoping the newer sensor had just failed.