Flashing overdrive light sometimes 95 F350
I have a 1995 f350 7.3 completely stock and just replaced the ECM because its was screwing up. The overdrive light will flash and when its flashing the trans will shift hard. sometimes pretty violent. Weird part is that sometimes the light will just turn off and everything will be normal with smooth nice shifts?? then anywhere from an hour to the longest being 5 days later it will come back on and repeat the cycle. Turning it off and on doesn't do anything but make it shift not quite as hard. Any input would be nice because this just weird to me, thanks!