My over drive light flashes intermitently. Mainly on deacceleration when coming to a stop. Overdrive button works fine. Tranny seems fine maybe a little harsh shifting under hard acceleration. 75 K miles on 94 4x4 250HD IDI. I've heard something about flashing codes. Is a Ford dealer the only one who can do this correctly? Should I change the tranny fluid and filter? Don't know if its ever been done.
thnx jvc

 

Try abottle of that slick 50, I think it mainly rejuvenates the fluid among other things, I have had good luck doing this believe it or not! It always scarses me to change fluid(some bad post experiences)

 

Have you ever reset the FIPL (TPS) sensor on the IP.

Do the speedo and tach work flawlessly........no bouncing etc.

Hold off on the snake oils till we get it fixed.

 

Ya I'm afraid of fluid and filter change as you guys are. Only had the truck a month. No resets. IP?

cheers jvc

 

The FIPL is the square sensor on the drivers side of the IP, you may need a Torx screwdriver in either 15 or 27.

Here is the info........
Hook up the negative lead of the volt meter to the battery ground and the positive lead to the center GY/W ( grey/white wire which is the FIPL signal wire), I use a paper clip up the side of the wire in the connector. The FIPL must be attached to the wiring harness. Engine low idle speed must be set to specs prior to adjusting the FIPL. Engine off key on........
With a warm engine, key on, engine off measure the voltage at the GY/W wire, if adjustment is required loosen either the bracket with bolts or just use the slack in the Torx screw holes. Now gently rotate the FIPL until you get some where between 1.05V and 1.1V. then tighten the torx screws or bolts which ever you loosened ensuring no movement of volt setting . Rotate the throttle lever to WOT see if you get 3.8 V but not more than 4.3 V.
The FIPL mounting bracket can be moved but ensure it is centered for a good rotation. Any adjustment should be made by only rotating the FIPL. If a new FIPL is required, check tang engagement as you take off the old FIPL and then make sure that the tangs in the new FIPL engage the throttle lever properly.
The closed throttle voltage: 1.1 V, .........wide open throttle voltage: minimum of 3.8 V but
not more than 4.3 V.


DIESEL FIPL SENSOR INFO
DATE 1992
REASON
Early Black FIPL has High Failure Rate
RECOMMENDATION
Always replace the black colored early FIPL or any colored FIPL having 60 thousand or more miles with the late gray colored FIPL.
PART NUMBER
F2TZ-9B989-C

 

Awesome info PLC7.3. My OD light flashes but only when the tranny is slipping a tad - high RPM, low speed, like when pulling out a tree or turning around in the bush with a load. Mine resets itself after a bit of normal running. This is a reman tranny that I have a shift kit on it to make the shifts firmer cause the previous tranny calved and had really sloppy shifting and the OD light always came on. That is the only experience with the light comming on. My understanding is that when the light comes on it throws a code and that code can be read by a dealer or with a code reader that you can buy yourself, although I can't remember the name of it. I have a great relationship with my dealer here, so they read it for free. Good luck.

 

BChunter Mine does the same thing when very cold, I do know I need a trans fluid change and filter ASAP, it's only been 100K miles since rebuild.

 

Now that I am focused on this OD light issue I realized it always comes on when braking???? Think I will establish a relationship with my dealer for a free flash! I'll print off and save the voltmeter stuff if they want bucks$$$$. Thanks guys.

jvc
hunter

 

Before doing that jvc100 check your fluid level in the brake resevior, move the float gently, check the wires connected to the M/C for security. Could be when you brake the fluid goes down enough to set the light.

 

Do a search on my name in the clutch, tranny, diff section.
I had this issue and posted so many times I can't even remember what the heck I posted.

But it is all there.

Pulling codes is very easy, I have detailed that method also in that same section.

When I had the issue, it turned out to be mostly my VSS with an incorrect voltage on the FIPL as well.
Got those fixed and the troubles went away.
Best volatge I got a WOT was 4.0

 

Great! Check the fluids tomorrow. Sounds stupid that I havent already but just bought it and had the guy's go over it with a fine toothed comb! Spent 2K since then. Found the tranny section which I never knew existed. Long scroll down. Searched and found Ironpants thread! Will pull the VSS off and replace.

thnx jvc

 

might was doing that and I cleaned all the connections to tranny and reset it and its been doing great...