I changed out the sensor on the rear axle which some called the vehicle speed sensor and some called the ABS. However it didn't fix the light flashing but did help with the shifting, the sensor was in pieces so it was definetly bad. I had two diagnostics done on mine and was told it was the planetary gear (there are no shavings in the tranny fluid and it works fine if you turn off the light), then was told it was going to be $1800 at the other place and no indication what it was there. Well if I turn off the light it works fine. If I leave the light on it shifts hard. I think there is another sensor somewhere but so far I have looked above the transmission, around it all along the transmission and drive train areas. I tried disconnecting the battery and resetting the system that did nothing. There are no other ones I can find anywhere so I drive without the light on and it works great. Good luck to you.

 

You might have a chafed wire on the top of the tranmission wiring harness. You'll have to disconnect all the plugs and work the harness down so you can examine the whole thing.

 

when the on/off flashes, the transmissions go into a "failsafe" mode only using gears 1,3, and 5, i am currently having this problem, it does this because the there is circuitry wrong somehwhere and the truck is recognizing it and entering this mode to keep form causing damage to the PCM. my mechanic told me to change out the 7 solenoids in the solenoid body, so where i stand right now is that the the transmission is getting confused on whether or not the solenoid are closed or not. so i ordered the solenoids and plan on replacing htem this weekend

 

What code did your mechanic say it throwing? Hopefully he did some diagnostic work cause there are other causes of the OD light flashing.

 

Only shifts 1,3 and 5 in failsafe?
What trans is this?

This tread is a mess with so many people with problems.
The only thing in common here is a flashing OD lamp.
Step 1 pull the codes! It will help to find the issue.

Bill

 

it happened to me today. I pulled codes!!! P0237 and P1728... now im off to see what they mean...

 

P0237 Turbo Boost Sensor A Circuit Low Input
P1728 Transmission Slip Error <pretty vague, eh?

Ford OBDII Diagnostic Trouble Codes - Powerstroke Diesel Codes .: Articles

 

Ice

Your truck has a E4OD and can only slip code in OD.
The E4 does not have an input sensor like the 4R100.
Most common cause for 1728 in the E4 is the TC clutch slipping.

Bill

 

see if you can get this, 95 psd, f350, std cab, long box, 4x4 bouncy speedo tranny shifts hard and no blinking o/d light

 

Thank you very much for getting back to me on that Bill.

I cleared the code out of my truck. It throws this code every couple of months and after I clear it, I dont have the problem for a while. Is there a possibility that its just a computer malfunction? If not, what would be a good TC or TC clutch (not sure if they are part of the same thing, don't know alot about trannys!) that I should choose?

-Brian

 

It is possible that the code is not real. That test doesn't work as well as it should. If it only sets the code every couple months I'd ignore it. If it gets to where it sets it frequently you'll need a new torque converter.

 

X2 on what Mark states.
On the E4 its a calculation of motor RPM and vehicle speed (mph).
If it falls outside the window of cal it codes. Could be a few reasons for it.
Just most of the time it ends up being the TC down the road.
I would ignore until issue is elevated.

Bill

 

ok thank you much mark & bill

 

My father and I replaced the rear vehicle speed sensor in my 1999 ford ranger and all is well thanks to the information earlier in this post.

I was having problems with hard shifting, no speedometer, over drive light was blinking, check engine light was on, and abs light was on. I took it to our neighborhood honk honk transmission shop and they were going to charge me 2000 plus dollars. They approved me for that much credit and refused to change my transmission fluid without signing wavers and scaring me into thinking I might not get it around the corner. I had the fluid changed by someone else and it was all good and well with a trick from another site that said to apply the emergency brake and run through the gears for a minute each. A month later and $150 and I am back in the business shifting very smooth...including a new filter and a bottle of transx. Not sure if the transx is necessary but certainly buy into regular transmission fluid and filter changes.