DanB, first off, make sure you search BEFORE you post. A quick search in this category would have yeilded many posts.
The O/D light blinking means the tranny detected a problem, and increased line pressure, which makes hard shifts.
And to further help:
Originally posted by unisys12:
The O/D light flashing means that the ECM (`puter) has found a problem with one of the sensors on the transmission. Most likely the solenoid block, which contains the shift solenoids. They maybe sticking, causing your forced shifts.
Try changing the fluid again, just to see if the extra cleaning will help. While at Autozone picking up the fluid, get them to pull any codes on the cars `puter. This can be very hit and miss though. Just because the O/D light was blinking, does not mean that the ECM set a hard code to memory. So don't be surprised if they can't see anything. If that is the case, your only option will be to take the car to shop and have them hook it up to a live scanner and allow them to test drive the car. This, live scanner, will allow them to watch every sensor on the car, while driving, and will also take a snap shot of all sensor activity in the event of a error or mishap. This will help you narrow down where the problem is.
