O/D off light flashes on and off. why?

[jsfordboy02]

1996 4.0 sport auto. The "o/d off" light on the dash has been flashing every once in a while. Why?

 

[01explorer2wd]

When mine did that it was a speed sensor. But then again my spedo didnt work or nothing.

 

[drdoom]

Same here

Not to hijack, but I have experienced the same flashing, usually after driving for a good while. I am interested to hear what others have to say. Thanks.

 

[GuardianSport]

I think it's a costly transmission issue. I'm waiting for the day mine starts.

 

[jsfordboy02]

When mine did that it was a speed sensor. But then again my spedo didnt work or nothing.

vehicle speed sensor or transmission speed sensor?

 

[01explorer2wd]

the transmission one.

 

[Johnny58]

Hello. Mine did the same. I got to scan it, and the problem is something related to one of the valvebody solenoids. After several weeks of the O/D light flashing, the next problem that came up was a 2nd to 3rd slippage. Now it has a new issue: no downshift to 1st gear after several miles driving. It needs to be forced manually into 1st gear. I'm getting a rebuilt valvebody to replace it.

 

[lugnuts55]

Mine did the same thing. I changed the fluid twice with a couple thousand miles in between changes. I added some Lucas Trans Fix and it worked very well for a long time. It has recently started failing to drop into low at stops but only occasionally. I believe it is the number 1 solenoid. I am not very familiar with Ford transmissions but everything I have read points to that solenoid.

I noticed something else this summer. When we had a string of days into the 90's, the problem was more prevalant. When it cooled down it worked better. I'm thinking about adding a trans cooler to the front of the radiator. I know that will not hurt it and it should help it last a little longer.

Johnny58, I don't know if you need to replace the valve body but if that's what you are going to do, I'll be interested to see how it works out for you. I am going to see about a solenoid. I haven't started looking around yet so I have no idea how much they cost and how readily available they are. I will probably do the work myself so I hope I can get a decent price on a solenoid.

I hope someone else has some ideas for this because it seems to be fairly common.

 

[jsfordboy02]

Are these seleniods and valve bodies internal or external on the transmission? I can do pretty much anything but I freakin hate transmissions.

 

[01explorer2wd]

Well see mine wouldnt down shift into 2nd I had to manually put into 2nd and after I replaced both the speed sencors I havnt had any promblems at all.But it could be something totally different with yours.

 

[lugnuts55]

jsfordboy02, the solenoids are attached to the valve body which is attached to the transmission case inside the oil pan. I have to read up on it again but I believe the solenoids are replaceable individually. I haven't started looking around yet so I hope I'm not giving you some wrong information.

 

[rego]

I recently paid $150 to a transmission rebuild shop to put a valve body I owned in. I bought all parts and fluid. Had qoutes from $150 to $300. It cured my harsh shifting. Also on a different Explorer a new VB solenoid corrected the not shifting to first problem.

 

[N1265]

from what I have heard, when the trans starts to have some problems it shifts into a "limp home mode " that jacks up the line pressure so you can still get home when on the road. The light flashes to tell you about the problem. this is why sometimes you may experiance hard / abnormal shifts.

I think I read somewhere that usually the valve body gasket blows out causing a drop in pressure, I think I also read that it will only allow you to start the car 12 times in "limp mode " to protect the trans, but if you disconnect the battery it clears the code and gives you another 12 starts, But don't quote me on it cause it's been a long time.

Any trans shop should be able to read the code and tell you what the problem is...

 

[GETMYBELTSON]

Are these seleniods and valve bodies internal or external on the transmission? I can do pretty much anything but I freakin hate transmissions.

If you're asking this question you should probably have a shop do it.

 

[jsfordboy02]

If you're asking this question you should probably have a shop do it.

I know right, lol! But I rebuilt the manual trans in my BII without really knowing what I was doing so I thought it might be worth a shot. Im changing the fluid and filter tonight, is there anywhere on here that diagrams these valve bodies that I can try and look to see what Im going after, or try and see if I can tell if that gasket is blown? Thanks guys!

 

[jsfordboy02]

from what I have heard, when the trans starts to have some problems it shifts into a "limp home mode " that jacks up the line pressure so you can still get home when on the road. The light flashes to tell you about the problem. this is why sometimes you may experiance hard / abnormal shifts.

I think I read somewhere that usually the valve body gasket blows out causing a drop in pressure, I think I also read that it will only allow you to start the car 12 times in "limp mode " to protect the trans, but if you disconnect the battery it clears the code and gives you another 12 starts, But don't quote me on it cause it's been a long time.

Any trans shop should be able to read the code and tell you what the problem is...

Is there only one valve body that this gasket blows out of, or is there more than one to check?

 

[lugnuts55]

rego, I am happy to hear that the solenoid fixed the issue of not going down to low at stops. I will have to start shopping for one. I don't know what it will cost but I can do the work myself. The rest of the trans operation is solid and smooth. Thanks for the info.

 

[jsfordboy02]

Changed the filter/fluid and added some lucus, worked better for a few short trips in town then light started back up. Took it to my trans shop and they confirmed that the trans and converter are going bad. Had to order a used tested on from a salvage yard. $650 for both, tested good, 30 day warranty, 123,000 miles. Mine has almost 170,000 miles.

 

[jsfordboy02]

Well, need a new trans and torque converter. Got it pulled put and the converter was rubbing the bellhousing, plenty of worn down metal there. Nice.