96 ford focus transmission overdrive dash light blinking after 5-10 min. engine revs in acceleration from stop but easing off the gas once or twice allows it to continue smoothly. do i have a minor or major issue?...thanks

Transmission band slipping.

check your throttle pedal position switch and your throttle position sensor

I’m happy to assist further over the phone at https://www.6ya.com/expert/brock_d67526d2a834c47e

Rough Running Engine - James on Engines #2 - Bell Performance

https://www.bellperformance.com/blog/rough-running-engine

Apr 21, 2015 - When diagnosing an engine with a rough idle, there are certain things that must be ... If the problem does not reoccur, the codes will be erased by the computer. ... when accelerating the vehicle, which causes a higher fuel demand. .... it was water in gas...added added Gas LineAntifreeze/Water Remover.

You need to clean the IAC again and also the throttle valve and bore, use only CRC brand Throttle body cleaner. After they are thoroughly cleaned disconnect the battery for 5 min's and then drive the car in varying condition for a few days. If that doesn't cure the issue you have more serious problems and will need a scan tool to look into the readings from the MAF, TPS and ECT sensors. High idle cold start is normal then slowly dropping after a few minutes. I assume you never had a check engine light. Correct?

Sounds like the o/d solenoid is bad electrically or plugged up. Probably, if the o/d light is blinking, it indicates and electrical problem with the shift solenoid, so it won't shift into overdrive.

The transmission is likeley in need of repair by a transmission technician who can diagnose, take it apart, and repair the part. It will not be cheap to do this, though.

Good luck on this repair.

Have the vehicle scanned.The overdrive light is like the check engine light for the transmission. There are transmission codes in the ecm if the overdrive light is blinking.

Overdrive is a lock up within the transmission. The other "gears" are fluid and belt driven. So, could be that the sensor that allows the overdrive to "lock" is dirty/faulty. A transmission shop should be able to tell you in a heart beat.

I had the same problem took it to the dealer and it was a sensor inside the transmission.

have someone scan it for transmission codes. Most likely it is your Torque Converter that is going out, but it could be a solenoid, What color was your fluid?

The blinking overdrive button is telling u that a serious fault has occurred in the electronic controls or a mechanical fault such as excess slippage is occurring.