Sorry for the lengthy post, but it describes in detail what's up. I have a 97 xlt, 4.0 sohc, 4 speed auto with o/d and 223,000 miles. Outside of ball joints, tires, brakes, and a couple of $2-300 fixes the thing drives great! Here's the issue: about 100,000 miles ago the o/d light started flashing during an extended highway trip. It stayed on the whole drive (total of a few hours). I stopped in the middle of the drive, turned off the engine for about twenty minutes and it was still on until the next morning. It only happens when I'm driving at higher speeds (60-80 mph). After the truck is off for maybe a couple of hours I can get in, turn it on, drive through the gears with a steady foot on the gas (not necessarily hard) and the light will go off. I know it's not good for the transmission to drive under the "hard shift" mode for extended periods of time, but there have been times when I've drove it in this mode for hundreds of miles. My experience has been that it started out happening about once every few weeks to now where it happens a couple of times a week. What's interesting is that I drive all around the highways in the Twin Cities and there seems to be a couple of specific points in/on the road that will trip the light -usually a slight/moderate uphill grade.

I've read posts here over the years and have had it into the ford garage a couple of times and they troubleshoot and don't know what it is, reset the sensor and I leave $$$$ down only to have it happen again. Now that I know how to clear it myself I've tried to ingore the repeating light. Any ideas? Is there a sensor I can disconnect/replace? Thanks for any response!!!!

 

My old lady's did that and then the tranny blew a few weeks later.

 

My 1999 did that for about a year. Took it in last week to see what was wrong. Getting a new touque converter installed now. Good luck.

 

Update on my 99... the torque converter did not do the trick. So they have ordered a new valve body. Funny thing is, only code has something to do with the air conditioner. Not sure what the code was, just what the tech. told me. The X has been in the shop 2 weeks now, sure glad its covered under warrenty. Had problems last year with shifting between 2 and 3. Ut Oh... better get...you know who.

 

sounds like a valve body gasket. read here

https://www.ford-trucks.com/article/...dy_Gasket.html

Matt