Mazda Forum - Mazda Enthusiast Forums - 99 Protege Flashing OD light

Hello everyone! Im here seeking advice. I am handy and can do my own repairs but i got something thats got me confused. OK so i just sold my 99 Mazda protege to an older women. 149k miles. Ran great always when i had it. but shes only owned it a few days now but when shes driving it the OD light random comes on and starts flashing and when it does that it almost scares the sh*t out of you because it feels like a downshift when your doing 50-60 mph. then the light will keep flashing until you pull over put the car in park is the only way it stops flashing. Now it does this here and there.. other then this no other transmission issues.. i was thinking possible speed sensor? when the light flashes you cant just push the OD button and turn it off..as stated you have to literally pull over put it in park so it stops flashing.. Any or ALL advice is much Appreciated ill be monitoring this post. Would really like to fix this for the elderly women who has health problems! Thank you everyone!