It's done that way because there are very different inputs, different wiring. Ford isn't the only ones to have done this.

Yes there are differences because Ford also updated engine wiring harnesses and made several changes over the years. In a nutshell, 99-01 PCM's are interchangeable (auto-auto, auto-manual, manual-manual, but not manual-auto). 02-03 are interchangeable with each other the same way.

However, you cannot put an 02 PCM in say a 00 truck, and vice versa. Inputs for various things are different because the engine wiring harness has changed when Ford made updates beginning in the 2002 model year. Case in point, your alternator will quit charging the batteries as an example.

PCM's are grouped as "families" or model type. For example you could have two different PCM's, one is a calibration PMT1, the other is a calibration YLE1. Both are actually part of the same family of DPC-422. PCM's of the same family can be reflashed to another calibration of the same family. So a YLE1 can be reflashed as a PMT1 for example. You cannot reflash if they are of a different family, but if they fall within the same model years of compatibility (99-01 or 02-03) and transmission compatibility, then they can be swapped out for another.

Here's a quick list of PCM's including calibrations, model type (family), applicable years, etc: PCM Codes - 1994-1997 Power Stroke FAQ

Clear as mud now?

 

The 02-03 PCM works just fine in a 99-01 vehicle, Curtis. The water in fuel light comes on and that's it.

 

Yeah but I don't like lights on the dash.....

 

this is good stuff...Thanks for the clarification, Cleatus.

i'll throw another bone in the mix....since "tuning" a trtansmission is mentioned, here's this that has popped up a few times in other threads/forums, which seem to be 'holding water"

Automatic Transmission Controller | Diesel Conversion Specialists or google "7.3 pcs controller"

 

I guess I don't understand the concern/confusion/question, Tim.

 

from what i intrepet the PCS controller, its jst that. Let the PCM do the air/fueling thing, and the PCS takes over the trans. Laptoping in whatever shiftpoints..etc, you want....something to that effect...guess i strayed abit OT, with this mentioning.....back to regular program, my bad.

 

That's how it works out, but not how Ford intended. Yes, Ford made specific automatic transmission PCMs and manual transmission PCMs. Ford did not intend for the PCMs to be interchanged but it just so happens (not really surprisingly) that if the need arises, an automatic transmission PCM will work and function in a manual transmission pickup. The automatic transmission PCM has the shift solenoid drivers, firmware, related hardware and programming to cause the automatic transmission to function. The manual transmission PCMs do not (some actually have shift speed mapping though because copying and pasting is a good way to save programming development costs). Everything else about the automatic and manual transmission pickups is the same as far as engine functionality is concerned although there are very slight tuning differences that many will never notice.

 

Pocket and cleatus12r,

Thank you both for your time and effort and priceless knowledge.

I now know more about the PCM than I ever dreamed of needing to know. The knowledge gained has been due to necessity for the most part....

Thank you both for your individual and collective contributions to it.

 

Not your bad. Your point just escaped me since it is morning and I slept in on my day off. I haven't gone to town to get coffee yet. This getting old thing is a beeeeeotch!!

Sometimes it would be nice to have a transmission controller that does not have hard-wired (and irreversible) idioms. Are there certain things that still aren't completely tunable (or untunable) using today's technology? Of course. However, for the vast majority of people out there, enough has been gained in the last few years to sway people from adding more aftermarket stuff to an otherwise reliable, stock vehicle ("stock" as in computer control systems). Stock wiring and computer controls means stock reliability.

Where the aftermarket controller crowd really comes into play is when a bunch of different parts are installed that without insane time investment and coin will NEVER function correctly with stock computer control (or wiring) systems. Two of many examples:

1. Using a 4R100 behind a common rail Cummins means that the Cummins computer has to be used to control the engine. A 7.3L PCM will not run a Cummins engine but would work for the transmission IF it could see all of the inputs from the engine side in the same way that it would "see" 7.3L data. The most important input, camshaft position and RPM, would not be supplied to the PCM in the way it needs to be fed. Other sensors such as accelerator pedal position could be adapted, but would involve a bit of creativity.

2. Using an Allison or 5R110 behind a 7.3L. While both of these transmissions could be adapted to 7.3L, the 7.3L PCM cannot control either one. The PCM for a 7.3L is a simple creation only having to output signals for a pressure solenoid, two shift solenoids, one coast clutch solenoid, and a torque converter clutch solenoid. For the 99-03 trucks, two of them are pulse width modulated while the other three are nothing more than an on and off. Both of the newer transmissions use a pulse width modulation strategy to apply/release the oncoming or offgoing clutch(es). Simply turning on and off a PWM style solenoid/valve setup has two drawbacks, both of which are really undesirable for both occupant comfort and reliability of the electronics. By using an aftermarket controller, the important inputs can be fed to the module wherein the calculations and programming can be sent to the transmission control outputs to make the thing function correctly because the stock engine computer just can't do it.

 

Cleatus12r and Pocket: I went through thedieselstop.com FAQ's and PCM list and I didn't see the E Series 7.3 listed. For us van guys, is there any difference between say a 2002 E350 7.3 PCM and a 2002 F350 7.3 PCM?
And isn't there also a 2003 E350 7.3?

 

Tell me about it. We are friggen blessed to have these two guys helping out The Brotherhood.

Stewart

 

A van PCM will not interchange (as in not work correctly at all) with a pickup PCM which is a bummer since ebay is full of van PCMs for a decent price.

Sorry.

What is your current PCM's code? I can tell you what to look for.

 

Not much to add... however I use my phone for the TQ app, if needed...

And to change settings on my chip via the Cyclops...

Nothing more to add...

 

MSG, reps to you for wanting to try and make something we could all use better and more cost effective. Everyone has to start somewhere. We wouldn't have what is out there today if someone didn't take a chance. There is times when I think it would be really nice to have this or that for a add on. It just comes down to time, experience, available equipment, drive and most of all the funds to take on such an adventure.

Take a chance, and prosper.

 

This one?