Well the OD light started to blink on and off today. It happened twice before but went away and didn't come back. Today it happened twice today. Both times exibiting no problems at all with shifting and overall performance. I talked to a reputable tranny shop in my town and he said he'll half to scan the computer and pull the tranny code ($55) and then determine whats wrong and then the proper fix. I also asked if it was just an electrical problem, he said its possible. So if it is, im getting a tranny flush and new filter ($150). I've had my fluid changed before and im coming up on the next change, could a dirty filter and fluid cause the light to come on and off?

Its just a blinking light with no rythym to it, just on/off.

 

what kind of vehicle and tranny is it?
A tranny guy told me that when the light blinks its usually a bad sensor.
You can purchase code readers really cheap and diagnose it yourself really easily.

 

The light blinking indicates an electrical problem such as solenoids or bad connections. Dirty fluid or filter will not activate the light.

 

my bad guys. Its a 97 f150 4x4 with the 4r70w tranny. I went to autozone when it happened the first time and had them use that actron obd2 scanner and nothing. The light wasn't blinking though.

 

When my 99 got the flashing O/D light, I came to this forum. One of the guys said, "Run, don't walk to the dealership" to determine the problem. It'll cost you some money, but may save you from grenading your transmission.

When the light is flashing, the tranny goes into a "limp-home" mode, where, as I understand it, the system operates at a high pressure to ensure shifts occur. The only symptom I had was a harsh downshift from 2 to 1. Running it that way is very unhealthy for the tranny.

My problem turned out to be a bad 2-3 shift actuator. I had the dude at the Dealership do the job, mostly because I have the 6/100 powertrain warranty. He showed me a box FULL of broken actuator springs from 4RW70 trannies.

As it turned out, there was something else wrong before the big problem occurred. Since I had purchased the truck, with 67K on it (fault occurred at 92K), it had always "hung" in passing gear. I had to "feather" the accelerator pedal after overtaking to get the thing to upshift back into overdrive. That went away with the rebuild.

Good luck!

 

When mine comes on there are no differences in the way it shifts, nothing. No harsh downshifts, no lagging upshifts. I know some have said that the blinking OD light may have a specific rythem to it. Also why wouldn't it come right back on after i turn the truck off?

 

I was told the flashing O/D light is the transmission's version of the "Check Engine" light. I'm not sure if the Autozone tester (or any of the other generic testers) will pick up a transmission code.

My advise is to go to the Dealership while the light is flashing, and spend the $$ to have the diagnostic done. If it's nothing, great. If you catch something before the tranny comes untogether, bonus!

Once again, Good Luck!

 

This is the thing though, the light may not come on for weeks.

 

Been awhile for me re: 4R70W... as I recall when o/d light blinks, a DTC has probably been set. Its stored in mem. even if light quits blinking. Also scanner will not read a DTC unless its programmed to read FMC specific a/t 4R70w codes.

If you disconnect battery for what ever reason, that will erase any DTC's that have been set, meaning a scanner want read until a DTC is set again.

Your saying your a/t seems to be working ok, just o/d light blinks off/on etc. Maybe it is ok, however I would clarify w/auto zone if their scanner can read your DTC's. Im thinking it want as OBD's show engine DTC's. If thats the case you might consider having it done elsewhere. Yeah I know it costs but might be worth it. JMO!

FWIW...just passing along. I found out that overfilling (a/t fluid) can cause a DTC (diagnotic trouble code) to be set.

Good luck....OT

 

autozone and my friends OBD II scanner from his school dont pick up tranny codes. I watched it come on the other day and nothing happened when it came on, no unusual shifting or noises. Im going to take it in on monday and see what ford says.

 

Seems to me like most of the OD flashing lights problems are due to the actuator pump malfunctioning. I think a lot of that depends on maintenance, but if it hasn't been done - maybe a good flush and new fluid will stop the problem for a while.

Then again an electrical problem is also possible. Would check into all the cheap and easy possibilities before replacing the tranny which is most likely what all the experts will tell you to do. I do agree with taking the truck to a good Ford dealer. At this point, most likely your best alternative.

 

Well im takin her in tomorrow at 1pm at pistilli ford. Great service department. Im having them pull the codes and not to work on it, there also going to take a look at the recall i have on my truck.

I do maintain it so i know its no abused. I had the fluid changed at 82k and im at 105k now. So its coming up and im going to have it done at a tranny shop.

 

Well I had the code pulled and it was the VSS. It would've been $125 installed at ford, but I opted to do it myself. Cost me $27.

Best part of all this is Pistilli Ford didn't even charge me for the computer scan, unlike all the other dealerships i've been to which charge $85 and up.

 

Yer a lucky man.

Now, go do something nice for somebody...keep that karma balanced and all.