HI, I drive a 1991 Lewis short school bus which is basically a Ford E350 (International). I have had it for about a month and a half. There's an intermittent problem with the overdrive light flashing. When it's flashing, the vehicle shifts a little harder and there's more pressure. Usually, turning the ignition off and then on again turns the light out. Last night that quick fix stopped working for about an hour, and I couldn't get the light to stop flashing. Today, all is well again. I have taken the bus to not one but 2 transmission shops, but unfortunately the lights was not flashing when I did, and there never seems to be an opportunity to bring it in while it is - it just seems to always happen at night. The only code that came up on the computer at either place was "pass." This led both shops to tell me there's nothing really wrong, that the problem is most likely just the sensor itself. Neither of them had time to actually deal with that problem until next week. Unfortunately, I begin a 3,000 mile road trip (yes, perfect timing). This trip can't be postponed for various reasons. Both transmission guys tell me I should be fine, just recycle the ignition if it happens again. I'm not feeling super comfortable with the idea of suddenly needing a transmission rebuild in the middle of Kansas, but I am also not comfortable (obviously) with throwing parts at the problem without knowing what the problem actually is. If the light blinks while either shop is open, I'll rush over there, but barring that... does anyone have any suggestions for me?

 

This is the exact issue I am having with my 1999 E350. Did you find any solutions?

 

When the OD light starts flashing , it is telling us there is a problem involving the trans.
The better thing to do is, have the vehicle checked for any codes. This can become a problem it the system resets every time you shut the key off.
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If you can , try to make a note of just what you and the vehicle are doing at the time it starts blinking, as you mentioned it seems to happen at night. That is important to know.
If we know what the conditions are when the problem appears, when we want to verify if the problem is fixed,we know how to bring it out if it is still present.
Can you do this?