My Overdrive light on the dash all of sudden starting flashing last night, and when accerelating the rpm's go up. Pushing the overdrive button on the gear shift does not help. Can someone help!

 

A good starting point would be to check the trans fluid level as instructed in the owner's manual. Then smell it. If it smells burned or even has a hint of burned, I would suspect the trans is slipping (internally of course), and if you keep using it in the present condition it could become quite expensive to correct. Have it checked out by a competent mechanic.,,,,,hanky