Wanting some opinions. ABS & VSS issues..

[7.3JeepHauler]

Hello everyone,

New to the site and wanting some opinions. Having the infamous Dead speedo, ABS light on solid, and Flashing O/D light.
And it was not a simple cleaning or swaping of the VSS for my fix unfortunately....

So far I have changed the diff fluid, check inside the carrier, tone ring looks fine. Nothing out of the normal.

First cleaned the VSS..Nothing..Then went to Ford for a new Motorcraft VSS..still nothing..

Have checked the wiring, and gets power to the rear diff sensor once the truck is put in drive, went threw fuses all checked out fine.

And earlier tonight even swapped out the ABS module from my dad's working module from his F350...and still nothing!

Any input would be greatly appreciated!! This is my daily at the moment and can't really drop it off to sit at someone's shop or pay a crazy amount to fix it.
Truck is a 2000 F250 supercab xlt 7.3 auto with only rear abs.

[JSchuricht]

It's dangerous and I hated doing it, but jack up the rear hookup a oscilloscope to the VSS signal and give her some gass. You can view the signal and see if it's clean comming in or not.

You might also try checking the wire or even running a temporary wire to verrify the stock wire isn't open or short.

[7.3JeepHauler]

Originally Posted by JSchuricht

It's dangerous and I hated doing it, but jack up the rear hookup a oscilloscope to the VSS signal and give her some gass. You can view the signal and see if it's clean comming in or not.

You might also try checking the wire or even running a temporary wire to verrify the stock wire isn't open or short.

I did something similiar to that last night. Got a buddy to get in the truck, put it in drive, and used a test light to make sure I had power back there. And being a 2 prong plug, one was hot, one was not, which was the ground im assuming. I did not use a multi-meter. But i know I am getting some kind of current back there..

[7.3JeepHauler]

Tonight I kinda found out that there were two "speed sensors" Diff one is the ABS and the one on the top of the Trans is the Tranny speed sensor...Well swapped that off from my Dad's 4R100 but no luck again!

[02whtmax]

Know this thread is a few months old, but im having the same problems on my 2000 v10 f250. Did you every find a fix for your problem? Changed and cleaned all sensors but have not drained fluid and cleaned housing yet, but i have managed to get the speedo to work will 10mph then bounces and drops to zero with o/d flashing right after the fall to 0 mph.

[7.3JeepHauler]

Hey sorry for the late response, Haven't been keeping up with all me emails like I should. But I did end up getting it fixed thankfully. It was wiring issue, caused it to continually short out, which therefore, burnt up my rear speed abs sensor on the top of the diff.
I myself checked it just with a test light to ensure it was getting power, but apparently it was grounding out or surging somewhere. Ended up taking it to ford, after I had first replaced the vss sensor with no luck, my wiring problem caused that one to get fried too.
Honestly didnt cost me too much about $200 with the new sensor. Which was better then me hunting down shorted wire throughout the truck. The cause was from "rodents" getting into some of my wiring, thankfully that was all they got a hold too.

[snow-junky]

I just had same problems.Replaced both sensors for less than a $100 and now i'm good. The one on top of the tranny is a fun one though.

[7.3JeepHauler]

Originally Posted by snow-junky

I just had same problems.Replaced both sensors for less than a $100 and now i'm good. The one on top of the tranny is a fun one though.

Well yours sounded like an easy fix. So you had both sensors go bad at the same time im assuming? and yes getting to the one at the top of the trans is a total pain, especially swapping mine around from my working doner's truck then no difference. Just glad i didnt fry every sensor i plugged in when trying to get a diagnosis before taking it to ford.

[02whtmax]

By any chance did you notice that the speedo needle would jump around when lets say you hit the window button or the door lock? This is driving me crazy and i dont want to take to dealer, the dealer here is a real douche. Did the dealer tell you where your problem wires were?

[7.3JeepHauler]

Originally Posted by 02whtmax

By any chance did you notice that the speedo needle would jump around when lets say you hit the window button or the door lock? This is driving me crazy and i dont want to take to dealer, the dealer here is a real douche. Did the dealer tell you where your problem wires were?

No mine quit all together just the next time i drove the truck it was completely dead. This was because it was a rodent issue the dealer told me. Which i can believe because we have found mice or squirrels tearing up the fire mats under the hood of my jeep before. So thankfully it was just somewhere under the truck and not inside on the main harness or anything too critical to operate.
Strangest part was mine was recieving current when i checked it but was just shorting out and spiking which destroyed the first oem sensor i replaced on my own.
Im guessing your having something shorting out too considering its interfering with other electrical operations.