Pcm swap???

I have an early 99 f250 auto 7.3. No junkyards around have a computer for my truck and they all claim that I can only use the computer I'm looking for. So much question is, can I use other year 99-01 powerstroke computers? As long as its automatic I figure it should work. Please correct me if I'm wrong

My computer is the xle8, or f81f-12a650-bk

Iirc, DPC-402 is the main part to pay attention to.
https://www.thedieselstop.com/faq/9497faq/geninfo/pcmcodes.php3

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79jasper said:

Iirc, DPC-402 is the main part to pay attention to.
https://www.thedieselstop.com/faq/9497faq/geninfo/pcmcodes.php3

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Click to expand...

See that's what I was thinking as well, but have also been told to try and find the pmt or nvk. Which are both the dpc422. Either way, every junkyard is telling me they have a small list of other computers that will work but they dont have them either. I'm half tempted to just go to a junkyard and do my own search. Or pay 250 to have it "rebuilt"

There might be an issue with the torque converter lock up. Early 99 are non PWM.
Late 99 to 03 are PWM.

trackspeeder said:

There might be an issue with the torque converter lock up. Early 99 are non PWM.
Late 99 to 03 are PWM.

Click to expand...

Help me with the terminology please... what's pwm?

79jasper said:

Iirc, DPC-402 is the main part to pay attention to.
https://www.thedieselstop.com/faq/9497faq/geninfo/pcmcodes.php3

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Click to expand...

This is correct. The module has to be the same due to wiring differences. So DPC-402 is the only ones that will work in your truck (FYI the last number 2 indicates automatic, a 1 at the end indicates manual transmision).

So you've got:

FUT
GLF
HPA
XLE

to chose from. There are slight differences for "warm" or "cold" weather (mainly GP strategy) but nothing that would keep it from running your truck.

I've got a DPC-401 PCM sitting in my garage from when I "upgraded" to the later PCM coding on my E99. So if you swapped to a manual transmission it would work in your truck!

Car-part.com is a great resource for PCMs.

greenskeeper said:

This is correct. The module has to be the same due to wiring differences. So DPC-402 is the only ones that will work in your truck (FYI the last number 2 indicates automatic, a 1 at the end indicates manual transmision).

So you've got:

FUT
GLF
HPA
XLE

to chose from. There are slight differences for "warm" or "cold" weather (mainly GP strategy) but nothing that would keep it from running your truck.

I've got a DPC-401 PCM sitting in my garage from when I "upgraded" to the later PCM coding on my E99. So if you swapped to a manual transmission it would work in your truck!

Car-part.com is a great resource for PCMs.

Click to expand...

So basically what everyone is saying here is I have to stick with an e99 only pcm (dpc402) basically because of torque converter issues? Here's another question. Say I'm the one that fried my computer in the first place by putting the "correct according to ford" gem module. Since it worked fine before i put the "correct" gem in it. Is that a possibilty that the gem module fried it?

90f250 said:

So basically what everyone is saying here is I have to stick with an e99 only pcm (dpc402) basically because of torque converter issues?

Click to expand...

Evidently, the E99 4R100/E4OD used the E4OD style of TC lockup - namely a solenoid that you turn on when you want lockup, and the speed at which it locks up is controlled by the size of the passage that the ATF can flow through(it's not instantanious). The upside of this is that it's 'easy' - lockup activation happens at one speed, no fancy control.
The downside is that you might want pressure faster at WOT vs at idle; you don't want it to bang into 'gear' or slip too much.

So, the later 4R100s used a PWM solenoid and a different fluid pump with bigger channels going to the TC lockup. Now, if you give that solenoid full power(100% duty-cycle), it'll engage just fine... but really really quickly. Anything less than WOT it'll clunk into lockup.
So the computer gives it a 'ramp' up when the TC is commanded to engage.

Personally, If I have to deal with that(last 4R100/E4OD swap I was playing with ended up just being a 5-speed swap; no PCM issues there!), I was thinking about building a small converter/ramp box that would just use a power transistor, resistor and capacitor to effectively give me my 'ramp' up("soft start" basically).

So, in your case, the TC lockup issue can be worked around several ways:
1. Unhook the TC lockup wire and cap it - No TC lockup, but at least you have 4 gears and a running truck, and can upgrade the TC lockup later.
2. Upgrade to a 4R100 trans from a later truck when you do the PCM upgrade.
3. Install a manual trans and not worry about the stupid lockup.

It does seem like my trans locks up and shifts kind of hard ever since it got rebuilt... wondering if they did a later model rebuilt kit in it or is that even a thing?

Macrobb said:

Evidently, the E99 4R100/E4OD used the E4OD style of TC lockup - namely a solenoid that you turn on when you want lockup, and the speed at which it locks up is controlled by the size of the passage that the ATF can flow through(it's not instantanious). The upside of this is that it's 'easy' - lockup activation happens at one speed, no fancy control.
The downside is that you might want pressure faster at WOT vs at idle; you don't want it to bang into 'gear' or slip too much.

So, the later 4R100s used a PWM solenoid and a different fluid pump with bigger channels going to the TC lockup. Now, if you give that solenoid full power(100% duty-cycle), it'll engage just fine... but really really quickly. Anything less than WOT it'll clunk into lockup.
So the computer gives it a 'ramp' up when the TC is commanded to engage.

Personally, If I have to deal with that(last 4R100/E4OD swap I was playing with ended up just being a 5-speed swap; no PCM issues there!), I was thinking about building a small converter/ramp box that would just use a power transistor, resistor and capacitor to effectively give me my 'ramp' up("soft start" basically).

So, in your case, the TC lockup issue can be worked around several ways:
1. Unhook the TC lockup wire and cap it - No TC lockup, but at least you have 4 gears and a running truck, and can upgrade the TC lockup later.
2. Upgrade to a 4R100 trans from a later truck when you do the PCM upgrade.
3. Install a manual trans and not worry about the stupid lockup.

Click to expand...

thank you! great explanation.

90f250 said:

Help me with the terminology please... what's pwm?

Click to expand...

Pulse Width Modulation

In this case, like Macrobb said, the E4OD/Early 4r100 just use an on/off solenoid. Think light switch, light off - no lockup, light on - lockup, but that light only has a pinhole to shine through. The light is on, but only a little light "leaks" through. If you looked at the controller output on an oscilloscope, it would be a square wave, but if it was disengaged, it would be off, engaged it would be on.... something like this:

___________________--------------------____________________--------------------

That it, all or nothing, a constant signal.....

PWM, the solenoid is controlled by a variable signal. Same light, but flip the switch really fast.... this time, the bulb has a larger hole for the light to go through, but the amount of light getting through is less, because the light isn't on 100% of the time.

So it would be controlled by a signal that looks like this:

____________----__________------_______--------______-----------_______---------------

Until it would eventually stay 100% to stay fully locked.

Or another way to look at it, non-PWM would be they way a lot of small engines are used, idle, or full throttle.... one or the other, PWM is like riding a skateboard... you start off slow, but the faster you go, your kicks get faster until you are going as fast as you can.....

This is how a lot of variable speed things are controlled now. For example, the electric cooling fans in newer vehicles...... they are not fed 12 volts through an on/off switch. They are fed 12 volts through a controller, that will quickly switch the 12 volts on and off to just "bump" the motor to maintain the speed. In the skateboard analogy, kicking just enough to maintain the constant speed you want to go.

That's a fantastic explanation thank you!

And although expensive...what are the options out there for a "new" pcm or remaned one? And have folks had much luck with them?
As these trucks are aging, I can see sourcing PCM's and IDM's becoming a major problem in the near future. They will all fail sooner or later. If they can't be sourced, that will spell the fate of these 7.3psd trucks I reckon.

I have a few high hour 7.3 psd service trucks and im at the point where I almost want to replace the computers with new ones BEFORE they fail.....but would need to be sure of the quality of the aftermarket replacements.

No idea. Just did a search though. Fs1inc advertises they program it, and lifetime warranty.

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