Hi everyone and thanks in advance for your help.

The truck in question is a 93 250 4x4.

It has been going into "limp mode" at random times, at varying speeds for no apparent reason. I've run the codes on it and found 23 (tps out of range) for the KOEO test and 29 (insufficient input from vehicle speed sensor) in continuous memory.

I've checked voltage at the tps sensor and it is within range with the engine off and no throttle input (.9V). I've traced it back to the connector on the passenger fender well, as well as cleaned and re-seated the firewall connector, but it still throws this code. Where should I look next?

The VSS has been recently replaced. Are there any common trouble spots I should look for in the wiring to track down this problem? The speedometer generally works fine. The only thing I have noticed is it will sometimes wiggle slightly at highway speeds.

Also, what is the trick to disconnecting the solenoid pack plug on the passenger side of the transmission? I've removed the heat shield and cleaned as much gunk as i could from it, but can't seem to find the clip or get enough grip to remove it.

Thanks again for your help,
Nate

 

The bulkhead connector is a stupid design. Ford later changed to something more "normal" that has a release tab like what the MLPS has on the other side of the tranny. Most guys end up getting a screw driver and breaking it (all the manuals specifically have a warning against doing this because it was happening so often).

There is a thumb tap that you need to press in, while pulling strait up on the wires at the same time. It should slide out but you might have to pull up on the wires from side to side slightly to get it to pop out. The the thumb tab is on the outer side of the connector and you are going to push toward the drivers side to unlock it. To reinstall it you simply push down until you hear a "click".

If that wasn't enough, the plastic is a brittle blend and will break easily if you press too hard on that tab.

 

I was having this issue So i took it to my Transmission guy (good friend of the family) to have a look, He said everything looks good just was giving a FIPL code and so I changed the FIPL to the newer one (I think black instead of grey). after that I still had the same issue. even though i would never get the harsh shifts or irregular shifting it would still flash the OD light would flash on 4-5 times per week. again I was not having the harsh shifting or any other problems.

then one day I was talking to a tranny guy that runs the hobby shop here on the navy base in panama city and he said that there is a sensor that when the fluid splashes around in the pan it sets off the OD light to limp mode. he stated the best fix was to add an extra qt of ATF. then the sensor would not get tripped.

I dont know much about transmissions and I have always called them the mystery box. but on the other hand i have not had one OD light flashing since I added that extra qt of ATF. has been about 1 year since.