I've got a blinking overdrive light in my Expedition. It won't turn off when I hit the button, either. The light doesn't start blinking until I start up the vehicle and drive for a minute or two. Also, when it's blinking and the truck shifts gears as I accelerate, it seems to shift rather hard. Any idea what this could be? Thanks.

 

the light blinkin means you have a electronic pressure control problem or sensor problem for the tranny. You can try changing the Tranny fluid and filter and see if that stops it.The shifting you are referring to is limp mode to keep you from damaging it further. Unfortunately you need a professional, you can't pull the tranny codes unless you have a good model scanner (1 or 2 grand), Get it checked ASAP! (I don't believe Autozone and Advance have the ability to pull these codes either!)

 

Thanks, 99. Considering I just had a complete transmission flush done about 5K miles ago, I doubt that changing the fluid and filter will help. I've got the mechanic working on it taking it to a place that he can get the codes read.

 

What was the diagnosis of your blinking O/D light? My buddy has the same issue, only his tranny won't go into reverse, and he said that it feels like it slips when he accellerates.

 

Did you have this problem solved, I'm experiencing it in my truck

 

You really need to take it some place where they can read the tranny codes. The flashing OD light just means it has a problem code. It could be a lot of different things. The flashing OD light is to the transmission what the "Check Engine" light is to the engine.

I had the OD light start flashing on 2 seperate occasions on a 2000 F150. First time the code was for the range selector switch, however after replacing it twice the Ford dealership finally replaced the ECM to fix the problem.

Second time the code said the tranny had overheated (which it hadn't). They replaced the temperature sensor in the pan and some connectors. Drove it another 60,000 after that before trading for my 2004 Expy without any further problems.

 

Mine had this problem last summer. Blinking overdrive light and would stall when driving off in first. I actually got it scanned with just a regular scanner and I got DTC P0743 I think. It was the TCC Solenoid. Bought one on Ebay for $50 and replaced it. Had to drop the tranny pan, drain fluid, unbolt old solenoid and replace it. This problem has also occurred from some parts of the wire harness to the tranny touching the exhaust manifold and melting the wires..

 

Thx,I'll have it scanned tomorrow, will chk this out, Have another code of "lean mix" & "check engine" is always on. I bougth this truck 1 yr ago and never turned a light on.... uff.

 

If you read your codes if your lean you should come up with p0401 and p0407. I had the same problem with mine. So I took off the throdle body and intake man. and all the Vaccum ports where full of carbon... and you could not blow air thru them. I took about 35 mins to take everything off. I clean the port out I used carb cleaner and a fine wire brush. then air blew everything off. If these ports are not clean it can not create a vaccum for your EGR Value so i will cause you motor to run lean and throw those codes. u mite also have a bad vaccum line. miine was the small line that runs from the smog box on the drive side firewall to the back vaccum port of the throdle body. U mite also have to replace your EGR. its the Silver tubing on top the intake mani. it works to clean it 40% of the time. but is best if replaced. takes about 3 hour from start to finsih. just make sure you use new gaskets and gasket seal when reinstalling. 6 gaskets in all. good luck.

 

BriR
The flashing OD light indicates a trans problem and your description of harsh shifts would indicate that you may have a broken spring in one of the accumulators, There are two of them. Accumulators,that is.

PabloCruz
Your buddy's problem may be the reverse servo spring.

Both of these problems cause strange pressure problems in the 4R70 and the 4R100 transmissions.

 

What was the problem? I am having the same issue

 

I have a simular problem but I don't have forth gear and when my o/d flashes the truck runs rough I have a spare tranny would it be better just switch them out or switch parts out in them

 

Correction...when your truck runs rough the tranny light will flash. The problem is more likely with the engine and not the tranny.

 

Nobody knows what's wrong with your truck. If you get the codes read, then we will be able to tell you where to start looking. You can change the trans, and you may have the same issue with the new one. Is the problem inside or outside the trans? Without the codes NOBODY knows the answer to that question.

Don't go to an auto parts store to read the codes. They can't read the codes that make the OD light flash.

 

1997 Expo XLT - 2 plus hours into a 5 hour drive I noticed the flashing OD "OFF" light. Hot Alabama summer driving. I drove it for another hour and noticed the rear hatch window dirty and I pulled off to get a drink from the Marathon gas station. Noticed a trail of oil following me and lots of tranny fluid coming out. Level checked about 1/2 qt or more low. Did not want to drive it like that without knowing what went wrong. Had it towed and had the codes checked, flushed and new kit installed with new filter. Returned home (5hour) driving at 60 - 65 mph and stopping at 1.5 hour intervals. It started leaking again and shifts rough in slow city driving. Mechanic who did the flush says it is probably the torque converter gone bad. PS light flashing continuously during my drive home. Guess I'll take her to a transmission shop.
Oh, Mark, the guy I took it to first did not tell me what the code was but that it suggests mulitple possibilities and he would start with the torque converter causing over heating of the fluid. But why would that cause it to leak? Is there a safety overflow for the tranny fluid???
I just called the mechanic and he said the code was P1728.