Ok i have a question, and it involves the flashing od light of death. lol so here is my story.
last wednesday, i had to go home for the weekend from school. well i typically cruise at around 75mph down the highway. any way after about 10 or 15 minutes, my od light started to flash at me. so i figured oh f#@&%. well i pulled off of the road, and reset the computer, and took off again. about 15 minutes later it did it again, and i reset the computer a second time. the third time it did it i just shut off the truck and started it back up. this time the light didnt come back on. i made it home and drove around through the end of the week and then i left home to come back to school today (sunday) and after about 15 minutes at 75 the light came back on again. well i stopped to get a bite to eat and shut off the truck and then continued on my way keeping it at or under 70 and the whole way back after that (around 80 miles) and no more light.
so basically anything under 70 i dont get a light. the wierd thing was i could abuse it all weekend with NO ISSUES. all the gears hooked up fine, no thumps or bumps, or wierd noises. when the light comes on, all the gears still seem fine, and the od button still functions. so what gives? am i boned?
i know i need to take it to ford and have them pull a code for me, but that wont happen for about a week and a half so im hoping someone will have some helpfull information untill then. Thanks!
also fluid level is good, and it is bright in color and doesnt smell burnt.

 

ok, so now that i am back home, i finally had the code pulled at a dealer. turns out it is the vss (vehicle speed sensor) from what they say, it is on the transfer case, and that when it is changed, you have to replace the fluid as well. the dealer wants 200 bucks for this and im thinkin um... hell no. they also want 175 for a trany flush. oh and they charged me 96 to plug the computer in to my truck.... so i dont want to give them any more of my money. i have the original transfer case from this truck. so my question is, is the speed sensor the sensor that you can see on the tail shaft of the case? how hard is it to replace? any info, photos, or anything constructive would be greatly appriciated. Thanks!

 

The VSS according to the manual is located at the rear section of the transmission. Code P0503 is a designated VSS and circuit control mode. Remove the electrical connection, remove the retaining screw, withdraw the VSS from the transmission case. reverse for installation. Does not say anything about fluid change being involved. I don't know what engine you have, but the part looks like 20 bucks for a 97 F150.

 

hey thanks for that. was that for a two wheel drive truck? because i am pretty sure, that the guy at the dealer said that mine was in my transfer case. which made sense to me because i think it reads the output shaft which drives the drive shaft, so on a two wheel drive it would just be in the end of the transmission. i will look tomoro and see what i can see, while im doing my oil change so hopefully this will get fixed in a day or two.

and i think they wanted to do the refill just to tack on a few more dollars to the bill. lol

 

Your transfer case uses automatic transmission fluid. It should be changed regulary, every 25,000 miles or so.
Easy to do and should be done if yours hasn't been drained & refilled in the last 2 years or 25,000 miles.
Good luck with your VSS change.

 

well this is not the original transfer case, it came from a truck that had about a hundred thousand on it and then it got wrecked. i put new fluid in it when i put it in about 6 thousand miles ago so i think i should be ok with that. i did the switch today, with the one from the original transfercase, and they both looked the same, the gears on bot were in good shape, so i am assuming the issue was internal in the sensor.