Hi,
New user here. I have owned two (still have one)1997 Ford F250 HD with 7.3 Power Stroke with E4OD transmissions.
I have the identical erratic shift issues on both trucks. One truck I bought new, the other used.

I purchased one truck out of state 1000 miles away from me in 2023.

This same issue has been on forums I read before, but I never saw the answer to this common problem. Any help would be very much appreciated.

Things i have done: replaced VSS, (ohm'd wires to rabs module). Speedometer works. Tested rabs module, its ok.
It's hard to believe I owned 2 separate trucks that were 1000 miles apart from each other and yet if you closed your eyes when the transmission acts up you wouldn't know which truck you were driving.

Thanks for help in finally getting an answer to this problem.

 

Define 'erratic shifting issues'.

 

With no description of what's wrong the best advice I can offer is to fix whatever is causing your problem.

The first step is ALWAYS read the codes. Use Forscan so that you'll get all of the codes.

 

Hi, thank you for the reply. The issues first started with my "red" truck. I bought this new. The problem first started while driving down the road. the truck seemed to slip into a "nuetral mode", it was corrected by shifting to nuetral then back to drive, it then drove normal again.

This problem began to happen more frequently. The same truck began to stretch out first gear, then hit second with a hard shift, then at times would not shift to third until I let up on throttle, then it shifts rough (most times now the OD light on automatic shifter would start blinking)

The truck then added another issue: when I exited off the freeway, the transmission once in a while would not down shift, and lurch at the stop sign.
The truck then progressed to yet another issue: I would be driving and all worked fine, come to a corner, slow down, when I pressed the gas pedal to go the truck would pop into a "nuetral" style mode and didnt want to go unless the rpm's were high and then just slipped the transmission along. All these things were intermittant.

On the red truck mentioned above, I replace the VSS, the pigtail for the VSS. I replaced the plug end pigtail to the transmission located on the passenger side of the truck. I also replaced the sensor on the foot feed as well. The truck was not a daily driver but I struggled with this driveability mode for about 7-10 years. I eventually gave up and sold the truck, and bought another one, same year, make, model in another state 1000 miles away.

The next truck is "white". The owner told me he had minor transmission problems, so he bought a new transmission from Ford and installed it. While driving this truck home on its 1000 mile journey, the SAME problems began happening!

With the white truck I replaced the VSS, a brand new Ford OEM foot feed, had the truck into a transmission shop, electrical shop, and no one can figure this out. What I can say about both trucks, at first, if I shut the truck off and re start it would run ok. On both trucks, I could shift manually to second, then back to Drive and it would be 50/50 if the truck drove normal.

Coincidence or not, the white truck I could shut the truck off, shake the wires on the drivers left and it would re start and run good for a while....coincidence or not I do not know.

Wow! I hope I covered most or all the quirks. Hope you have some insight.

Thank you.

 

Hi, thank you for the reply. The issues first started with my "red" truck. I bought this new. The problem first started while driving down the road. the truck seemed to slip into a "nuetral mode", it was corrected by shifting to nuetral then back to drive, it then drove normal again.

This problem began to happen more frequently. The same truck began to stretch out first gear, then hit second with a hard shift, then at times would not shift to third until I let up on throttle, then it shifts rough (most times now the OD light on automatic shifter would start blinking)

The truck then added another issue: when I exited off the freeway, the transmission once in a while would not down shift, and lurch at the stop sign.
The truck then progressed to yet another issue: I would be driving and all worked fine, come to a corner, slow down, when I pressed the gas pedal to go the truck would pop into a "nuetral" style mode and didnt want to go unless the rpm's were high and then just slipped the transmission along. All these things were intermittant.

On the red truck mentioned above, I replace the VSS, the pigtail for the VSS. I replaced the plug end pigtail to the transmission located on the passenger side of the truck. I also replaced the sensor on the foot feed as well. The truck was not a daily driver but I struggled with this driveability mode for about 7-10 years. I eventually gave up and sold the truck, and bought another one, same year, make, model in another state 1000 miles away.

The next truck is "white". The owner told me he had minor transmission problems, so he bought a new transmission from Ford and installed it. While driving this truck home on its 1000 mile journey, the SAME problems began happening!

With the white truck I replaced the VSS, a brand new Ford OEM foot feed, had the truck into a transmission shop, electrical shop, and no one can figure this out. What I can say about both trucks, at first, if I shut the truck off and re start it would run ok. On both trucks, I could shift manually to second, then back to Drive and it would be 50/50 if the truck drove normal.

Coincidence or not, the white truck I could shut the truck off, shake the wires on the drivers left and it would re start and run good for a while....coincidence or not I do not know.

Wow! I hope I covered most or all the quirks. Hope you have some insight.

Thank you.

 

The only code that came up on the white truck was the foot feed. Replaced that with a brand new oem foot feed. Problem still exists. My speedometer still works, so I believe that indicated my VSS works?

 

A bad MLPS (Manual Lever Position Sensor, also called the TRS - Transmission Range Sensor) located on the driver's side of the trans is almost certainly the cause of the problems on both trucks.

As they age they send a false signal to the PCM that you've moved the shift lever to N. The PCM obliges because it thinks that's what you want. When you move the shifter it goes back to working for a while and everything works until it happens again. Replacing the pigtail to it won't help anything, the sensor is bad. Change it.

With the red truck you could have read the codes and it would have told you where to look.

 

Thank you for your diagnosis. I bought a new one tonight. I will put it in tomorrow, take it out for a drive and let you know how the truck performs.

Again thank you.

Craig

 

I hope to read your findings if only to better acquaint myself with this sort of issue. Best of luck on your repair!

 

Good morning. I will let you know today. I am putting the new part in soon.

 

Hi,
Update after the installation of a new TRS switch. After I installed the new switch, I backed out of the driveway and moved forward. Withing 50 feet my OD light started to flash on the shift lever and the transmission strung out 1st gear and hit 2nd real hard. I kept driving and the shifting was hard from 2-3 and 3-4.
I kept driving up to 65 mph (up and down speeds) and the transmission kept hard shifting (but no "nuetral" type modes).

I went hope to scan the truck after the first drive. I had a PO500 (VSS), but that could have been from before and not cleared. I cleared the code and re-tested.
The truck drove much smoother on shifts after clearing the code.

Question: Is there a "re-learn" for the computer after the TRS module?

The OEM Ford module I took out is part #F5TP-7F293-AA. I replaced it with a Napa part #NS6528.

I will continue driving the truck later today, and tomorrow. I will re-post how the truck drives then.

Thank you for helping with your responses and guidance.

Craig

 

There is not. The part either works or it doesn't.

 

Good morning.
I drove the truck to church this morning. I brought my solus pro with. I was watching the speedometer reading in the transmission section.
The speed completely dropped to "0" and that's when the transmission acted up once again with long hard shifts, and the "nuetral " style operation.
The OD light started flashing on the shifter again.

My dash board speedometer was still functioning as normal.
From reading forums and talkiing with a transmission shop they said if the VSS was bad, the dash speedometer would not work?
I have replaced the VSS on this truck (with o Ford oem) and the pigtail leading to it.
Do I have a bad ground?

Thanks for any help.

Craig

 

I'll bet you have a problem with the PSOM (Programmable Speedometer/Odometer Module.) It's located on the back of the instrument cluster.

The VSS sends the signal to the PSOM. The PSOM feeds the dash and the PCM, I believe from separate outputs. So the output to the dash could be fine and the one to the PCM is not.

There are companies around that repair PSOMs. New ones are not available.

 

I recently sent my PSOM to the repair shop to get rebuilt. I looked into how this works. The way I understand it is there is a sine wave signal that the entire truck uses, except for the Engine and Cruise control ECU. Those control units like to see a square wave. What changes the sine to a square? The PSOM. It is certainly possible that that portion of the PSOM is bad so the square wave signal is no good, but the speedo works fine.

The speed sensor in the rear differential sends out the sine wave in my 95 F250.