I’m hoping someone has suggestions for me. My 1994 E-350 overdrive button light starts to flash for no reason and it causes the automatic trans to shift terribly .the light starts and stops flashing for no reason. When it’s not flashing everything is great.

so far I have.
1. Changed shift lever new ford one
2. New ford TPI Sensor
3. New ford speed sensor

Anyone have any ideas what the problem is?

 

If it's flashing you have trouble codes on your trans computer. Should be plenty of info out there on what pins to jump and check what they are. There are a couple of very knowledgeable guys here with the e40d I'm sure will be happy to help if you can get the codes.

Most scanners won't read em, I think the snap on mt2500 is one of the only ones

 

Here is an easy way to read the codes: https://www.troublecodes.net/ford/

Without the codes all I can tell you is that something is wrong. As you've already found out just guessing at what to change is a waste of money.

 

one thing I can say is IF codes Clear by themselves then you probably have wiring issues either Internal to the E4OD or External, my experience has taught me that when components Fail they generally stay Failed... intermittent issues are a Bitch to troubleshoot as when you do pinpoints all the tests are good.

But as Mark says, you need to try extract codes and then do the pinpoint tests just because you get a code does not mean that what the code says is a Failed component, but it might lead you to the area of interest.

as an example Low Fluid in the E4OD will generally set the OD light to constant ON, there are no mechanical Failures just low Fluid level <<<<<==== Tell me how the Tranny knows that as it don't have a Level sensor, and I'm talking a cold Tranny so the Temp Sensor didn't set the code ?????

But for sure I have seen this dozens of times

 

So you're saying that low fluid turns off the overdrive? How does that work?

 

Right, I've been trying to understand how that can happen myself since the only sensor that tells the Puter anything is the "Temp Sensor" and I made note of the Tranny being Cold at the time....... I would have said BS myself if I hadn't personally seen it happen on my truck.

so what happens that can cause the OD to be canceled and not be able too turn it back on by pressing the button ?

I'm sure this is not a "Feature" of the E4OD, something has to happen related to low Fluid, but not the level itself.... is it possibly something to do with the wiring ??

 

It is either something wrong with the wiring or the PCM. Low fluid was a coincidence.

 

This was always my thoughts too, it was weird, but as I say I have personally seen it, I'm really leaning toward some buggy wiring issue.


the exact way that I have seen it happen is........ go out first thing in morning turn key to Run Position, OD lamp is off, hit GP switch for 3 secs, crank engine it starts then OD Cancel Lamp Lights and will not turn of by pressing the button, the Lamp is lit steady not flashing.

So then turn truck off, check fluid and none showing on the stick, I think I added like 3 quarts, <<<==== Yes I know you check Fluid while Running and Hot, but if it is cold and none is showing on the stick then it is for sure Low.


Well, after the Fluid Add, fire the truck up and all is normal and OD Lamp never comes back on.

also to Clarify I have had this happen to me Personally at least 4 times in the first year that I owned the truck,, I bought the truck in 1999, and I have tried to restart the truck several times when the OD Lamp was lit before I first realized that it was low on Fluid, and the Lamp persisted until I topped off the fluid level. I'm sure it is Coincidence but Man that's just weird

My First guess on an issue like the OD staying Canceled would be the 3 small wires to the button inside the Steering Column