Speedo, ABS, and AT Problems

[redwoody]

After 7 years of trouble-free performance, I finally had some problems while towing over the weekend. not sure if they are all related or not.

1) the yellow "ABS" light is lit on the dash full time
2) the "OD" light on the AT gear selector flashes intermittently. seems to flash primarily under acceleration and at slow speeds. trans temps are staying around 150. occasionally up to 180. trans seems to shift fine. no slipping as far as I can tell.
3) the speedometer only works at speeds above about 38mph. any slower and it reads zero. as soon as you hit about 38, the speedo needle gets a spark and bounces up to what I figure is the actual speed. seems to work as usual from 38mph on up.

The truck now has about 57k miles. I have not pulled any codes yet. I was hoping to learn more from you experts before I take it to a shop and have the computer scanned.

I would greatly appreciate any input.

[MrJohnWayne]

I'm not sure if ford uses a speed/abs sensor or if they are seperate units. Seems to me that is the problem!

[westcoaststrokin]

BUMPIN for ya!

[2005F250]

It could be your pcm could be sensors. My moms truck a 2000 had the same problems and it was the pcm.

[redwoody]

Originally Posted by 2005F250

It could be your pcm could be sensors. My moms truck a 2000 had the same problems and it was the pcm.

the pcm? the main computer!
OUCH! how much $$ ???
I wonder what I could have done to make it crap out?

[gparrow]

Mine did the same thing. Try the Speed Sensor on the top of the rear differential, not sure of the part # I think I had to get mine from the dealer.

[redwoody]

Originally Posted by gparrow

Mine did the same thing. Try the Speed Sensor on the top of the rear differential, not sure of the part # I think I had to get mine from the dealer.

you da man! that was it. only $42 for a new one. cleared the codes in the computer and no more! seems this sensor works with:

1) the ABS (reason the light was on)
2) speedometer (not registering under 40mph)
3) transmission shifting

I need to drive it more to make certain we got it but all looks good so far. thanks for the help.

[2005F250]

sweet looks like you don't need a pcm.

[tboydva]

How timely, my 00' F-350 just spawned the same problem! Speedo bottoms out at about 25 mph, but otherwise just the same (manual tranny though)... Do you know the part number that fixed your issue? I was trying to find it on Powerstrokeshop, but so far no luck. Would like to order and replace after getting in hand (need to commute). Thanks so much in advance...

Tom

[Big AL]

Originally Posted by redwoody

you da man! that was it. only $42 for a new one. cleared the codes in the computer and no more! seems this sensor works with:

1) the ABS (reason the light was on)
2) speedometer (not registering under 40mph)
3) transmission shifting

I need to drive it more to make certain we got it but all looks good so far. thanks for the help.

Man, glad you got that fixed easily!