5 or 6 years ago when I had a 5.2 2wd I bought a Mopar High Performance Computer. P5249516 1992–93 5.2L Magnum Dakota I did notice some power gains. But even with other small performance parts it was not enough for me. So I did the 5.9 Magnum swap. Ever since my 5.9 has been running off of the 5.2 Mopar HP Comp. It has run perfectly. So I never thought to change it, even though I knew it wasn't letting my 5.9 run 100%.

I was going to buy a 2nd Optima battery for my truck. My most recent 2nd battery was donated to my new Suzuki SUV. But after thinking of my most recent performance parts (1.7 Rockers, 53mm TB) and them not being able to reach their full potential I decided to go for the 5.9 Mopar HP Comp.

I bought mine off of www.Summitracing.com I found a few cheaper sites, like $5 -10 less. But I trust Summit. With shipping it was $278. P5249546 1994 – 95 Ram 5.9L Magnum. I just received it today. Easiest performance part to install it only took 1-2 minutes.

The full power increase will take a few days for the computer to completely learn my engine setup. But my first impression is that it feels GREAT! I lowered my PSI on my tires to 20PSI, for some offroading the other day. With the old PCM with lower PSI it was rare I could peel out on a takeoff. With the new PCM and low PSI it gives a long peel out great every time. I used to feel a drop off in power once it gets into the higher RPM’s. I suspect that it was due to the old PCM going into closed loop for WOT and running off of 5.2 parameters. So now the high RPM’s feel smooth and good power. I will report what else I feel within the new few days. I only test drove the truck for 10-15 minutes.

Also the cruise control works but I haven't been able to get it activated below 40mph. But I only tested the CC for 2-3 minutes. The manual says stock is a minimum of 25 or 30mph, with the old computer it was 35mph.

At the same time I ordered the new PCM I ordered up some Autolite 3922 spark plugs, which are 2 steps colder than stock. They will be in on Wednesday. I was starting to get some pinging with the old PCM. The new PCM may take care of that but they were $13 shipped from Amazon. I will see if I need them. Right now I have Autolite 3923 1 step colder range plugs.

 

Nice!!! Its about time! :P

 

how much for your old performance pcm...

 

The old one is going to a friend that I work with. He has a ram which it will work for.

 

Congrats Crazy. It sounds like you got a really good gain out of this mod. I wouldn’t be too concerned about cruise control not operating below 40 mph. The 5.9 performance computer will have some different parameters then your performance 5.2. I’m running the same computer and I’ve noticed lockup engages differently than with my stock computer. It still works fine but seems to be delayed a little before it kicks in. I’ve never checked to see if my cruise control works below 40 mph, I only use it on the highway.
I’ve had some pinging issues as well. I switched to 3923’s and it almost went away but was still there in some cases (right around 4000 rpm). About 6 weeks ago I had a fuel injector code. Back when I did my engine swap I used crimp connectors to connect the new fuel injector pigtails to my wiring harness. About 4 weeks ago I went back through and soldered all of those connections. Since then I haven’t noticed any pinging and the engine runs smoother and stronger. I’m also more careful where I gas up; I think some stations 93 octane is not really 93 octane.

 

curse you! lol jk

 

LOL Sorry! Keep checking www.ebay.com and www.craigslist.org You can find good deals.

 

Okay since installed the 5.9 MP PCM it feels great. Good HP but the TQ is more noticeable.

I have gotten a few codes off and on. With the old I didn't get anything. Even swapping back to it to test for the codes, Nothing!

So far
27 fuel injector miss. Injector #5 and another time #6. I think due to a loose connectors. The clips are broken.
23 Manifold air temp to high. The connector wires were cracked up due to heat, and shorting out.
Those have been taken care of.
21 O2 sensor to high, I'll try to clean up the sensor in carb cleaner.

The only problem I need help on is code 37 which is not a Check engine light code. I checked the codes with my Auto X-Ray code reader it tells me:
37 Transmission Temperature sensor to high.
And it is not 37 TCC. I unplugged the transmission connector and then it gives me 37 TCC, so it is different. If I remember right the Rams did have a Trans Temp Sensor in 94-95 and Dakotas did not.


(Update) I have a fix for this on the 2nd page of this post!

 

I’ve had almost the same codes you have, but over about a year. As I mentioned above my fuel injector code related to my not soldering the pigtails originally. I replaced the sensor three times to get rid of the code 23. It hasn’t come back for about a year now. I also have a code 37 present when I check codes. I think your right that a 93 Dakota doesn’t have a transmission temp sensor, I suspect we would have seen it if it had one. If you find out where it is on a 94 or 95 ram I’d like to know. I’m guessing it’s on the transmission lines or at the radiator. Since the code 37 is a soft code I haven't worried about it. If the check engine light was staring me in the face I'd have to fix it.

I haven’t had the code 21 but I replaced my O2 sensor when I did the engine swap.

 

Well I definately get all the transmission codes, 37 included... but it doesn't apply to me from the manual swap.

But yeah, all the transmission codes, the EGR code (since I don't have it anymore) and occasionally 17... but that usually happens in the winter when its cold.