1998 F150 flashing Overdrive Light

Jul 19, 2026 Last reply: 10 hours ago 2 Replies

Recently learned my transmission fluid filler tube has rusted out, seems the ear off it to the eng has rusted free, so it swings around loose and is hard to find unless you reach in the back and move it back into pos. I have a new one ready to go in this week, however today the Overdrive light on the shifter handle was flashing.



Apparently it means a code has been thrown, didn't look at the ODB yet, and no real issues I can tell in shifting at all but watched these videos:



formatting link
formatting link
Going to see if the wire bundle heated up laying against the manifold, turns out after I saw the light flashing, I went under the hood with eng running and grabbed the filler tube to reposition it and get a feel if indeed its still inserted into the trans case, and it seems like it is.



I read maybe dirt or rust can enter the tube if its got holes in it from rust, that I don't know but I am hoping the filter would catch the few particles that enter and if it was severe there would have been shifting issues by now but I don't feel any at all.



I plan to get a fluid and filter change soon anyhow just in case, but was curious what this wiring short can do....could it really fool the torque converter thru a solenoid or sensor and cause issues?


Update

I went under to look at the filler tube, its rusted in half about halfway to center.....the ear with the bolt is still connected to the block ok.

Looks like someone put tape or something around the break, some kind of vinyl sleeve maybe.

Thursday a shop will be putting the new one in for me and checking the fluid level. OD light has not flashed, I notice maybe some difference in shifting, taking longer from

2-3rd gear maybe but not all the time. Im figuring its probably a little low on fluid.

I threw the OBD reader in there this morning got:

P1537/P1538 (Already known , IMRC solenoids)

P0136:

If you can Easily get to the O2 sensor pins then you could check the heater ohms. Or, if the sensor can be removed without destroying it then you can bench test the heater ohms and also sensor volts with a propane torch. At least that would confirm sensor condition before checking the really difficult to check wiring.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required