Overdrive Light Flashing

[Dick Berg]

1997 Eddie Bauer 4 Liter, SOHC engine, 5R55E tranny.
My Grandson reported that the O/D light is flashing at a constant rate.
The check engine light is not illuminated. Could there still be stored codes? I have a basic code reader, but haven't connected it yet. If the check engine light isn't illuminated, would there still be some useful codes stored?
Can anyone advise what this means, and is it serious?
I see similar posts that suggest removing the negative battery terminal for a while. Should I try this?
Original tranny, 150K miles. We dropped the pan and replaced the filter and fluid about 500 miles ago. Could this be related?

Thanks,
stepdadbob

 

[Mbrooks420]

A flashing OD light is the check engine light of the transmission. Most basic code readers won’t read them.

I wouldn’t pull the negative terminal until you have the codes, although the likelihood of that fixing anything is going to very slim.

 

[C420sailor]

Auto parts store may be able to pull the codes. Your reader may work, depending on how basic it is.

No symptoms at all? Does it engage all five gears? Do you get torque converter lockup? Many of these transmissions end up throwing codes around that mileage for a burnt up torque converter that won’t lock up anymore

Codes will help

 

[410Fortune]

flashing OD light is what we call LIMP MODE
designed to get you to the nearest dealer for transmission repairs
Sometimes you will experience harsh shifts because the transmission is running at full line pressure
There are indeed codes in memory now, manufacture specific codes very likely

It could be anything from a simple failed speed sensor, or shift solenoid to a blown trans.
The codes are needed, the computer is telling you where to look


dropping the pan and changing the fluid SOMETIMES will release some carbon bits or materials from the valve body passages which can make their way downstream and clog things up.... Or you could have pinched a wire? not likely though.... Usually problems start when people do a flush (hooked to a machine that pushes fluid through trans) not a simple pan drop and filter change

 

[Dick Berg]

Thanks to all for the responses.
I just spoke to my Grandson who reported that the truck seems to run fine. Around town at lower speeds, the light goes off. It's only at highway speeds that the light illuminates. Even at highway speeds (65 mph) it runs smoothly.
He scanned it and there were no codes to report. As noted earlier, the check engine light is off. If we take it to a place with a more advanced scanner, could it show some codes that may be related to the light coming on at highway speeds?
Note that we were very careful when we dropped the pan and changed the filter and fluid, so it's not likely we did anything to cause the symptoms.
Do you think it's dangerous to drive the truck?

Thanks again,
stepdadbob

 

[C420sailor]

Mine did the same thing. Fine around town, after about 10mins at highway speed, TC would unlock and OD OFF light would flash. Drove smooth, but slightly higher rpm in top gear.

I’d drive it as little as possible. If you have to, you have to. But I’d get those codes ASAP.

 

[Mbrooks420]

If the light is flashing there are certainly codes.

 

[Dick Berg]

Thanks very much for the information.
For the time being, does it make sense to turn off the O/D via the pushbutton at the end of the shift lever so that the tranny doesn't even try to go into O/D?

 

[Fix4Dirt]

Thanks very much for the information.
For the time being, does it make sense to turn off the O/D via the pushbutton at the end of the shift lever so that the tranny doesn't even try to go into O/D?

imo the flashing OD is just more of a trans light to tell ya theres an issue similiar to a CEL, its not necessarily indicating a problem with OD i think. now it could be an OD issue which could be caused by it. so its an it depends, cause it comes on on highway it could be an OD issue. if he kicks it out of od does that continue to happen?

 

[Mbrooks420]

Your issue is more likely the torque converter as mentioned above.

 

[410Fortune]

Look the truck is going to run fine
there is an issue with the transmission
It could be so many things we can only guess
Your 5r55e automatic transmission is actually a 4 speed
This transmission uses 1st gear and overdrive to create a fake second gear
Then it also has a lock up converter which will lock and unlock just before the 5th gear (actualkly 4) shift
All of this is controlled by solenoids in the transmissions valve body
The valve body gaskets are known to develop leaks
The solenoids wear out
There are also other parts that wear out or can cause issues
The flashing OD light indicates a issue with the transmission that the computer is noticing.
Right now it is intermittent
It might get worse
There are codes in memory
It could be as simple as swapping a speed sensor, or you may need a solenoid inside the trans, or the converter wore out, or the valve body gaskets are leaking, or aa accumulator piston is stuck, or a band is wearing out, or a .................. you see where I am going?
The codes will TELL YOU/US where to look

Just driving around "guessing" it will only get worse
We cannot tell you if driving around with the OD off will help or not because we do not know what is wrong
Only the PCM does!

A good scanner can easily retrieve the codes
You can have it scanned or you can get a scanner....either way WRITE DOWN THE CODES
do not just take some autozone scanner jockeys word for it, write down the actual code numbers/letters

hope this helps

 

[Dick Berg]

Thanks to all for their inputs and suggestions.
Unfortunately, the truck died last night. My Grandson was driving it and it bit the dust. The rig would barely move with the engine racing and in all forward gears. We had to push it into a shopping center parking lot (not easy), and I'm currently contacting transmission repair shops to get an estimate.
It sounds like the TC to me, but after 150K miles, the whole transmission needs to be rebuilt. Do you agree?
Do you suggest getting an already rebuilt transmission installed, or having the transmission shop rebuild it and reinstall it? Or, doesn't it matter?
I'm in the San Jose, CA area, and I'm expecting a $3K+ bill for the whole replacement. Does that sound about right?
Should I consider having the shop rebuild the transfer case also?

Thanks again for all of the help.

stepdadbob

 

[Mbrooks420]

I’d put the money towards something better. With gas prices verging in insanity, and the fact you have the ticking time bomb of the SOHC I wouldn’t waste my money. That tranny rebuild is gonna seem much more unreasonable when it’s followed by a 3k charge to pull the motor and replace some cheesy guides and tensioners.

 

[Fix4Dirt]

Thanks to all for their inputs and suggestions.
Unfortunately, the truck died last night. My Grandson was driving it and it bit the dust. The rig would barely move with the engine racing and in all forward gears. We had to push it into a shopping center parking lot (not easy), and I'm currently contacting transmission repair shops to get an estimate.
It sounds like the TC to me, but after 150K miles, the whole transmission needs to be rebuilt. Do you agree?
Do you suggest getting an already rebuilt transmission installed, or having the transmission shop rebuild it and reinstall it? Or, doesn't it matter?
I'm in the San Jose, CA area, and I'm expecting a $3K+ bill for the whole replacement. Does that sound about right?
Should I consider having the shop rebuild the transfer case also?

Thanks again for all of the help.

stepdadbob

imo the 5r55e is a good trans, and with a frw mods can work quite well in the long haul. that being said, i may just put the money torward a decent v8. if the trnsioenrs and guides are already done, then maybe id keep the sohc, dpeending on all the other conditions rust etc. whats available in ya atea?

 

[mototyme]

1997 Eddie Bauer 4 Liter, SOHC engine, 5R55E tranny.
My Grandson reported that the O/D light is flashing at a constant rate.
The check engine light is not illuminated. Could there still be stored codes? I have a basic code reader, but haven't connected it yet. If the check engine light isn't illuminated, would there still be some useful codes stored?
Can anyone advise what this means, and is it serious?
I see similar posts that suggest removing the negative battery terminal for a while. Should I try this?
Original tranny, 150K miles. We dropped the pan and replaced the filter and fluid about 500 miles ago. Could this be related?

Thanks,
stepdadbob

When the OD light flashes the transmission will go into "Safe" mode and you might notice hard up and down shifting. Check the transmission error codes. One of the possible errors could be the output shaft speed does not match the input shaft speed meaning this is slippage somewhere. Also, the speed senor could be failing. Most error code readers don't read the transmission codes.