O/D light flashing

[Ray Ramos]

I have 5R55E tranny. 1998 ford explorer.
O/D light comes on,drive with it on for a few miles. Then light goes off. Vehicle drives fine. Until light flashes. Hard clunk, hard shift 2ND to 3rd or when slowing down 3rd to 2nd. I've got a P1740 and a P0720 codes. Can someone help me,as to what I need to do. I bought this vehice a month ago. I can't afford a shop doing the work.so I'll tackle this myself. Thank you in advance for any help you all can give me

 

[Mickalo]

I would start by checking your Output Speed Sensor on the trany and/or the wiring to the sensor from the control unit.

 

[Ray Ramos]

I would start by checking your Output Speed Sensor on the trany and/or the wiring to the sensor from the control unit.

I'll try that . Thanks for the advice.

 

[Texas97x]

Not to hijack your thread but I have a similar problem. Bought a 2000 Explorer with 4.0L OHV with the 5R55E. Guy said the OD light started flashing and he just parked it. I drove it home and no OD light flashing was present. Now it does have a bad tach that stays stuck on 4500 RPM most of the time, can tap on dash sometimes it will drop to around 1500 RPM but it is not displaying the actual RPM In either case. So it seemed to drive fine the next day when I drove it to work about 30 miles almost all highway, approx 5 miles city on the begining and end of the drive. On the way home when it was much warmer outside the OD light started flashing when I was a few miles from home and it seemed like it had very little power. Once it OD light started flashing it seems like I am taking off in 2 or 3rd. Not too sure if it is actually shifting up past 3rd gear and due to tach problem it is very hard to tell. Any suggestions on where to start?

 

[imp]

@Texas97x
If you can find a cheapie tach that works with EEC-V, a temporary hook-up could help diagnosis of shifts. Most I've seen, though, are EEC-IV or earlier, only. imp

 

[bloudon]

Appears to be an old thread, but here we go. I have a 2002 Explorer with just over 200K miles and the flashing O/D Off light just started coming on after driving a bit. I don't feel any hard shifting, but the warning light does seem to come on when a top O/D gear would be expected. I ran code checks and found the following codes using Forscan. C1284, p0174, p0741, p1151

Not sure if we're looking at the MAF Sensor, Torque converter solenoid or what. Any advice is appreciated.

 

[JK080]

The P0741 code is what is triggering the OD light to flash, the code is set when the computer does not see a rpm drop when engaging the converter clutch.

Unfortunately there is a few reasons why the converter clutch wont come on, from problems with the pump or valve body or solenoid to the converter itself. The only things you can do short of pulling the transmission out is to replace the solenoids or replace or repair the valve body.

I have noticed that if the converter clutch works when the transmission is relatively cold and loses the converter clutch when hot it's more likely a worn out valve body or blown out valve body gaskets.

 

[bloudon]

Thank you! It does take several seconds as you first put it in D after pulling out of the driveway in R and switching to D.

I watched a video on the valve body and solenoids. Looks fairly complicated but doable. What would that cost in a shop?

 

[C420sailor]

It’s def DIY if you have basic tools plus the proper torque wrench (inch lbs iirc).

The wildcard is the exhaust. If you have the SOHC, getting the exhaust out of the way of the pan is a pain in the ass.

Once that’s gone? Easy peasy.

I had the 0741 code on my 4R70W tranny and it was just the solenoid.

But I also had the 0741 code on my 5R55E and the converter lockup clutch was roasted.

It’s a dice roll.

 

[bloudon]

Appears to be an old thread, but here we go. I have a 2002 Explorer with just over 200K miles and the flashing O/D Off light just started coming on after driving a bit. I don't feel any hard shifting, but the warning light does seem to come on when a top O/D gear would be expected. I ran code checks and found the following codes using Forscan. C1284, p0174, p0741, p1151

Not sure if we're looking at the MAF Sensor, Torque converter solenoid or what. Any advice is appreciated.

It’s def DIY if you have basic tools plus the proper torque wrench (inch lbs iirc).

The wildcard is the exhaust. If you have the SOHC, getting the exhaust out of the way of the pan is a pain in the ass.

Once that’s gone? Easy peasy.

I had the 0741 code on my 4R70W tranny and it was just the solenoid.

But I also had the 0741 code on my 5R55E and the converter lockup clutch was roasted.

It’s a dice roll.

Well I took the Pan down and found a hairy magnet and closer to brown then red on the Mercon. I pulled the solenoid pack and valve body down. The screen filter in the solenoid pack has no goop or metal in it and I don't see any visible issues on the gasket once I removed the valve body cover. Trying to determine my next steps and what I should replace if anything other than the filter and gasket since I have come this far. Any suggestions are appreciated. Thanks!

 

[bloudon]

Well I took the Pan down and found a hairy magnet and closer to brown then red on the Mercon. I pulled the solenoid pack and valve body down. The screen filter in the solenoid pack has no goop or metal in it and I don't see any visible issues on the gasket once I removed the valve body cover. Trying to determine my next steps and what I should replace if anything other than the filter and gasket since I have come this far. Any suggestions are appreciated. Thanks!

View attachment 446190

View attachment 446191

View attachment 446192

I did find some brass looking shavings on the top of the filter when dropped. I guess I am going to try a replacement solenoid block and a new gasket and trans filter and hope for the best from here.

 

[410Fortune]

Cut the filter open and have a look
Brass shavings on top of filter not good