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View Full Version : 03 f150 4.2L 4x2 change 4R70W transmission; now haivng speedometer going 100 when 20



rzzzzx
04-04-2013, 07:22 PM
03 f150 4.2L 4x2 with automatic 4R70W transmission
JUST CHANGE transmission no leaks;
however the speedometer is having problem;
when turn on the pickup; and gas padeled, the speedometer is going itself to 100 when I am driving 20 miles !
everything else is working fine !
any help appreciated.
of what I hear online it is VSS or abs speed sensor issues, help !

RhinoZ24
04-04-2013, 07:35 PM
It sounds like the VSS because that is measuring how fast your drive shaft it spinning. If you changed the fluid, or had a shop do it. It may have been hit or knocked or something to where it is throwing off the reading.

lee reece
04-04-2013, 08:03 PM
If its vss there it would set code and would see light on dash come on normally!

Sent from my iPhone using F150 App

rzzzzx
04-05-2013, 08:24 AM
there is no indicator of a problem light on dash board.

I think of what I hear online; there are 3 speed sensor on transmission;
1. output shaft speed (OSS) sensor (left driver side)
2. digital transmission range sensor (left driver side)
3. Vehicle speed sensor VSS (rear of the transmission)
and
4. abs speed sensor (rear end of the axcle)

of what I hear, if it is VSS then it is connected to the gear; when taking out and putting you have to very careful as not to damage th gear teeth ! also online if pre -99 f150 then you have to add teeth to decrease the speedometer reading! but of after 2001 I think you got to program ??

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I let the shop do it; now they saying it is electrical problem ! if they knock off sometimes how do you change VSS ? also do you have program since it is a 2003 f150 ?

RhinoZ24
04-05-2013, 11:46 AM
You most likely have to program it because everything has gone computerized. Not like the good old days. That's probably what the shop will do.

rzzzzx
04-05-2013, 08:00 PM
I unplug the OSS sensor on the tranny and disable the speedometer and the car works fine.
however no speedometer; something is shorting it; could be fuse or ?

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there is no VSS ; only
OSS (sensor output shaft speed) sensor and
DTR digital transmission range sensor
+ abs speed sensor on rear end.
replace OSS with the old OSS no change

RhinoZ24
04-05-2013, 09:27 PM
It could be a short. Did you say you took it to a shop? Did you ask them if you did?