Overdrive light blinks/hard shifting

[fordboy324]

My overdrive light blinks and shifts hard. Its fine for abou 5 minutes then it blinks and shifts hard. Ive heard it was the VSS? I am unplugging my batteries each night to reset the computer and its fine for the day but then does it the next. HELP!

 

[FordGuy100]

Yup, your tranny is going into limp mode. The hard shifts are from it running up the line preasure so it doesnt slip as much between shifts. Causes less wear and tear when the tranny is failing.

It could be because of many things. It could be a bad sensor, or dirty sensor. I would start out, by taking all the sensors and wiring out, and clean it all up. If that doesnt work, maybe start replacing some sensors. And if that doesnt work, it looks like rebuild time.

If I were you, smell your tranny fluid, and see if it smells burnt. Drop the pan, and at the bottom of the tranny pan there is a magnent, see if any metal has collected around it. When my dads torque converter went (went into limp mode, we drove it that way for a good 5K miles, just unplugging it at night), there was a big donut looking ring of metal around the magnent, a good 3" in diamter, and 3/4" tall, a lot of metal. If you pull the pan and dont find any metal, put in some new ATF, and see if that fixes things. If not, rebuild time.

 

[fordboy324]

I think its the sensor because it shifts totally fine and doesnt slip at all when the tranny isnt in limp mode. The tranny fluid is red like it should be and not brown. I sold my old truck because of that . The sensor sounds like what it could be. The tranny has been rebuilt I just dont know when.

 

[suv7734]

When the OD light is blinking the computer will store a code or codes. Take a run down to Autozone or whatever is close and get them to pull the code(s) for you. That will help you narrow down what is causing the problem.

 

[fordboy324]

I will do that tommorow if it does it.

 

[Andylad13]

remember the codes you get are going to have multiple descriptions, only pay attention to the ones regarding transmissions. i would check the FIPL adjustment sooner than later.

 

[fordboy324]

What is the FIPL. Remember I am 16 with minimal knowledge but I have all the tools I need for anything. Im quick to learn so feel free to explain.

 

[LCAM-01XA]

FIPL = TPS, tis the plastic thingie on the driver side of the injection pump, if you stand before the grille and look at your engine it will be kinda behind the oil fill neck. It gots three wires connected to it, when you decided to check it for adjustment tis the middle wire you should be reading voltage off.

 

[Diesel JD]

Whatever you do you need to make sure not to ignore it. Sounds like you wan t o learn and have access to tools which is good. I'm glad I never had to learn about the E4OD, cause it is real picky about the settings on that FIPL, Gary(Icanfixall) and a couple others should have exact specs for what voltage you want to see there. The few people that have had good luck with that transmission have kept the fluid changed very often and flushed the tranny lines with clean ATF before adding new etc. and kept that FIPL in proper adjustment. For the long term, if you like and want to keep this truck for a long while, you should probably look into having your E4OD "built" at least to 97 and later specs but preferably by someone like Brian at Brian's Truck Shop, or swapping to a manual.

 

[LCAM-01XA]

FIPL voltage should be about 1.1V at idle, and between 3.8 and 4.3V at WOT, measured at the middle of the three wires with the engine warm but OFF, key ON. Odd thing is, the folks over at TDS say the 4.3V can actually be 4.5V, but under no conditions should it go higher!

Also, that Brian fella, is he by any chance somewhere in PA?

 

[pat_da_man]

i had my overdrive light randomly start blinking one day on my old truck i brought it back to the shop where the trany was rebuilt and they replaced a speed senor and changed the fluid and was good to go

 

[fordboy324]

where is the VSS on the tranny located?