97 F150 4x4 Reg cab, full bed. 4.2 V6 4R70W automatic tranny (Door sticker Tranny code "U") . 107,000 miles

Hi all,

I have checked the threads and while my issues is common, I have other things that make it different. Maybe you can help????

Won't shift out of 1st. PLEASE read all of post because it's differences may be something other than the range sensor. (Thank you)

At one point the OD went into limp mode. It no longer flashes so I am guessing that is because it is stuck in 1st now.

I have changed the Range Sensor twice. The original one that I took off looks like it heated up and started to melt the plastic casing. I put a new one on but that did not fix the issue. I replaced that one with another new one. (both new for 2 different parts stores) When I drilled out the rivets of the 1st new one, the inside plastic piece was broken. The 2nd new one is currently on, but still won't shift out of 1st HOWEVER it does start in Park and Neutral. The original one that failed was a 12 pin. The replacements are both 11 pin but said they work with 11 and 12 pin.

I was thinking of changing the speed sensor on the axle BUT (here is where it's different than most) my speedometer DOES work. It shows correct speed (compared to GPS). Also, I have do not have back up lights. (I have hot wired a switch for now). I have pulled all the fuses from under the dash as well as under the hood. All are good. (Slight short in box at the dome light (#10 I think) but nothing else is affected.

I think there are still 2 more sensors (mounted on the tranny) 1 is input and the other is output. If speedometer is working, wouldn't that mean one of them is working? Is there a way to test them with a jumper? I do not have a code reader. I have a multimeter, but I do not know how to test these sensors.

To sum up:
Won't shift out of 1st.
Changed range sensor twice.
Reverse works.
Back up lights do NOT work.
Pulled Neutral Safety Switch (?) and cleaned.
Speedometer works.
Don't know which sensor is input or output.
Don't know how to test, or bypass.
Do not know codes from check engine light being on.
ABS light is NOT on.

Any and all help is appreciated.
I'm not a mechanic by any means. Just a DIY guy trying to keep his truck on the road.

 

The range sensor and the neutral safety switch are the same part. Did you change it twice, then clean it?

You can't test the input and output speed sensors without a high quality scan tool. And you'd be wasting you time, anyway. They are not the problem.

I think the problem is with the wiring to the range sensor. I believe it is damaged and all the new range sensors in the world are not going to fix a damaged wire or connector. Get out your multimeter and wiring diagrams and check the wiring to the range sensor from the PCM.

 

I thought they were the same. But when I was under the truck, I pulled a sensor

which I thought was the neutral safety switch only because it screwed into the transmission, had a 2 pin plug/wire and the part that gets inserted into the tranny has a ball bearing on the end. I thought this was somehow used to only let the truck start when in park or neutral.
I'll see if I have any issues with the wiring and will post back. Hope its an easy fix that way!

Here is what my range sensor looked like too...




Hard to see, but above the bolt hole on the right is where it was burning and melting the plastic.





You can see directly above the shaft hole, it was broke completely off. I don't know if it was broke when I bought it or if I did it trying to put it on.





Still the 11 pin





Both halves side by side

 

Did that sensor screw into a port towards the front of the trans, on the driver's side, just above the pan?

 

Just passed the pan (going towards tailgate) on the driver's side. The tip that screws in faces the tailgate. The ball-bearing also pushes in but must be spring loaded too cause it instantly pushes right back.

 

Your trying to do repairs by being to tight, cleaning a critical part instead of replacing it with a proper part.
Some after market sources are not usable on Ford vehicles.
Get the correct one to be sure your not introducing another issue.
.
The TRS signals the computer on a 1 out of 3 basis to tell it what to do with signals to open and close transmission solenoids that control fluid flow for shifting. It's sort of a round trip loop action.
Reverse does not require any solenoid operation but the pressure control solenoid operation because there is no gear shifting that takes place.
The rpm and throttle application and road speed signals only add to when this all happens on up shift and down shifts.
If it won't go past first gear, it's not road speed related.
Get the new proper part then proceed to inspect for harness damage as Mark suggests.
As well have a look with a good Scanner for codes that involve the transmission as a backup to tell you what's going on.
Be sure fuse #23 is not blown.
If you don't follow a proper procedure, it results in confusion, hassle and parts you don't need.
Good luck.

 

That sensor is in the transfer case, not the transmission. It has nothing to do with transmission shifting.

 

Just as a follow up,
I wrecked in a snow storm and totaled the truck. I have since replaced it with a 98 explorer. Thank you all for your help though.