I'm in the market for a new PCM. Anyone know if the one for the 5.9 and 5.2 engines are the same? Wasn't sure if they just reprogram themselves to the type of engine or if they are preprogramed and taylored to each engine displacement to run more efficently.

I hacked my old PCM apart, for anyone who wants pictures of it, I got them, just ask. No need in explaining how to get it apart, no matter how you do it you'll ruin it everytime. I was really surprised how it was built inside and made, nothing LIKE what I expected at all.

 

please post pictures of the inside

and the pcm for the 5.2 and 5.9 are similar, and the 5.9 will run w/ a 5.2 pcm, but will not run 100%, it is NOT to be used as a long term solution. you can buy pcms on ebay pre-flashed to your truck for a reasonable price, then they are just plug and play once you get em

 

I got a good deal on one at a bone yard for $25 for a 5.9 PCM, but no sense is buying it if it's not exactly what I need. Then there's the programming fee at the dealer.

I'll get those pictures on tonight once I find my camera. When I plugged the PCM back in after I opened it, a bunch of relays just kept clicking, sounded like a machine gun going off under my hood, and the fuel pump never stopped priming. And of course it didn't start, and probably a bunch of other stuff didn't work. The pictures will explain it all.

 

Alright found the pictures, here's what a PCM looks like inside.


So this is attempting to pry it apart, it's RTVed all around to keep it sealed. There is an aluminum block in the middle and the outside casing is aluminum as well. So opening it basically makes the outter case bend and once that happens it's dead.


Basically here is the middle core with the outter shell (which has all the ICs and circuits glued to it) bend completely out from both sides. It basically just folds around the middle part like so.


And finally the picture you all been waiting for (I think) this is the outter shell folded open. Basically it's a huge ribbon cable type circuit board with all the ICs and components soldered to it. The back of the orange ribbon cable on steroids is glued very well to the aluminum shell. My best guess for them doing it this way is to get rid of the heat faster to the casing. But once you bend that outter shell you'll most likey pry up an IC off the board or something and kill it.
For any of you who took apart a CTM or other modules, the PCM inside is also fully coated in that rubber like clear stuff to keep moisture out.

If anyone has any questions at all about it, just ask, I have it sitting on my desk just because it looks cool haha.

 

So for anyone wondering, went to the service center at the Dodge dealer and the guy said the 5.2 and 5.9 PCMs are the same for my model year, but he wasn't sure if it had to be programmed or not. I got a PCM from a 5.9 D from a friend to try and the engine fired right up with a high rev then evened out nicely.

Also I didn't have to do any programming, it was just plug and pray, but it worked perfect, my mileage was correct and drove fine.

I don't think the VIN number or any specific vehicle information is stored on the PCM, at least for my 98 model that is. I could never pull the VIN out the OBD port anyways and was thinking what other modules in the car could be used to verify or detect a different PCM installed, for you 01+ owners maybe the ABS controller or possibly CTM, if Chrysler did require the PCM to be programmed for later model Ds.

 

i was under the impression that the vin# needs to match on all electronic control modules (abs, ctm, pcm) in order for them to function properly

 

I can confirm on my 98 D there's nothing that needs to be programmed. Since the parts guy was unsure about programming the PCM, I don't know if that was required shortly after or if he was just trying to get some money out of me. If I had to put a year on when these things had to be programmed, I'd say maybe 00 but most likely 01+ since everything changed and the CCD bus was overhauled. My 03 Stratus I know needs to be programmed for sure with at least the VIN because I can pull that right up from the OBD port with a scantool, but my D would never split it out. The crysler part numbers on both PCMs were the same, but the bigger bold numbers were different on the sticker.

So far I've swapped out the cluster, CTM and now the PCM and it's all just plug and play. I heard the ABS module was a pretty big important computer for the car too, I haven't messed with that but it seems to do quite a bit in the odometer mileage and vehicle speed department.

The thing that really got me was the dealer was ready and willing to do a reprogram for me for $140. Knowing them, they'd just plug in the new one and say yup all programmed now where's our $140. Not sure if this is sticky or FAQ material here but it certainly will save people money at dishonest dealers.

 

If you use the same type 1998-1999 5.9L to 5.9L they should work just fine. Same with 2000-2002 and I think 2003 but unsure. You can also swap a 5.2L PCM from the match years I just posted into a 5.9L and it's going to run, just not to its full potential. You can swap a 5.9L PCM (again using the match years I provided) into a 5.2L, with a boast of more performance (but haven't had anyone test this theory yet).

A 4.7L must be swapped with its exact match because of the 16 and 32 bit systems.

Anyway, I have seen this done a few times as the VIN doesn’t have to match. She should fire. The instrument cluster holds the mileage not the PCM. The reason for it to be flashed is the 5.2L and 5.9L are the same PCM only with a little difference in flash. There are other differences from what I've seen in the earlier years to later years 5.9L (as indicated above in the years) so the newer and later years are not swappable without a flash, in fact I would think they are completely different PCM's.

Now I have everyone confussed, better go to work now........

 

When I get some gas in it I'll take it for a little drive and see if there is an increase in performance and/or decrease in MPGs to test the 5.2L engine with a 5.9 PCM theory. I'll keep you guys posted on what I find out.

 

One of the biggest issues is if it has security, a security PCM will need to be flashed by the dealer to work in another vehicle. I have a non security pcm in my non security Dakota, I put in a non security MP PCM and it started up right away, tried one with security and it would not start. I am assuming that your Durangos were non security, otherwise the swap should not have worked. In addition, R/T PCM's have a different tune for their 5.9 that differs from the one in a SLT or other Durango with a 5.9.