So all of a sudden the ABS light comes on when I am driving and the speed odemeter drops to 0mph real quick and then the ABS light goes off and the odemeter goes back to normal speed. It seems to happen if I am going any speed. Just got back from a road trip and It has been doing this every 15 mins or so off and on. I may be a simple fix but before I just drove it down to the dealership I thought I would ask the pros first!

 

You could try and pull the speed sensor (VSS) from the top of the rear diff and clean it off or you could just replace it. It is fairly cheap and a good place to start. Might wanna inspect the wiring and connection while you're under there.

 

Yup, sounds like the VSS... ok, I hear an echo again...

 

Mine just started doing this, also I just noticed this morning while parked with engine running I could hear the ABS (motor module?) under the hood turning off and on.
While driving have you noticed when the ABS and Speedo do their thing the truck will slightly hesitate or hiccup?

 

I haven't noticed it hesitate, all I noticed is the speedo and abs light going crazy. It hasn't done it in awhile and I haven't messed with the VSS or anything yet. Maybe only with a load it does it?

 

Hmmmm...could be a crossed/frayed/shorted/worn wire??

 

The "with a load" makes sense, if the sensor is experience a heat-related failure.

Many sensors get like that - they break internally, and when heated, the connection breaks. Cool off, it's fine.

The rear end gets warm/hot when you're towing/loaded, that's for sure

So, yeah, definitely sounds like a heat-related thing. Change it anyway ...

 

I tow a trailer just about every day. My f350 did it regardless of towing or not. When it first started doing this it was only when I released the E brake and was backing up, now its when ever the mood strikes it.

As a trouble shooting step I have pulled the ABS fuse, ABS light is on all the time, however the speedo no longer drops out.

The hesitation might have been a partial operator error.
Changed the fuel filter and air filter, much smoother now. (fuel filter - 78.5k miles, air filter - 40+k miles)

I looked at the VSS thing but did not dig into it at the time, I was to upset that I needed a tool to take the fuel filter off.

 

My F250 V10 is doing this exact thing, random brake light with a simultaneous engine stutter and mph/rpm gage going to zero, did anyone figure this mystery out?