2001 300M PHP ECM question

Ronbo said:

Ummmm......what initiated this drastic change? Something in your current item set failed and you needed an entire set to replace it. The major fail on what you bought appears to be no keys/ignition lock to go with the rest of the set.

Did you need a new key originally or something else? I think I have a couple of Sentry key blanks here if that was the original issue. They're actually pretty cheap nowadays. If you don't have two original programmed Sentry keys...it's a trip to the dealer anyway. No matter if you buy a used complete set or not.

Click to expand...

My car currently has an issue with the ignition lock cable not functioning properly, which will be solved by replacing the column that I bought from Dave. At the moment, the interlock cable is unhooked, and the car drives fine. I'm going to use my current cylinder and sentry key with the new column, so that problem will be solved.

I do however only have a single sentry key, but it's not really a concern at the moment.

The 2001 PHP ECM that I was considering swapping into my car is a different topic all together. Reading through older threads it was stated that an upgraded ECM will result in better performance. I read that if you have an 98-01 then the 2001 300M PHP is the best possible ECM you can get because the 2002 300M special ECM will not work.

Check!

I come across a 2001 300M PHP in the yard so I figured, why not pull the ECM, SKIM module, and BCM. Knowing already that the swap would be more difficult without the sentry keys that came with it, I figured that either a dealer or Ross can program my sentry key to work just fine with the 2001 300M PHP ECM.

I read that for in order for this ECM to work in my car, since my car falls into the 98-01 range, that I MUST get the BCM from the donor car as well. After speaking the Steph, this BCM swap isn't feasible because I have a base BCM and the PHP has a premium BCM, which is physically different. Not sure if any member has done a base to premium BCM swap or not but I imagine matching all the pin outs would not be fun.

Anyways the need for the BCM is beside the point (other than giving me full functionning EVIC) because Brando26 actually tried putting a 2001 300M PHP ECM in his 2000 300M (I just found this out) and sure enough, he didn't have to swap in the BCM from the donor car. However, he did report:

The computer would expect to see side air bags, a different ambient temperature sensor (battery) and additional emissions components. While these lights will be on on the dashboard, the car will run with no issues whatsoever.

Click to expand...

See here: http://www.lhforums.net/forums/showthread.php?20029-FS-2001-PHP-ECM-n-stuff

So the question at this point is whether or not this change is worth it. Not sure what would have to be re-wired such that the car would throw no codes after the swap.

With that said, if the 2001 PHP doesn't change the shift points and only offers a little bit more power over my stock ECM, is it really worth doing the swap if I don't have the sentry keys that comes with it and thus I have to deal with extra re-wiring, the need to the scan tool, and additional part changes?

Then of course there's the whole, if your going to get it done, get it done right. Well that would involve doing what Dan did by swapping in the entire 2002 300M special harness. At that point, the car is worthy enough to accept a 2002-2004 3.5 stroked out to the 4.0. I read that there's some issues with making an earlier year 3.5 into a 4L, so this would be the route to go.

YesImLDS said:

But by switching to a 2.7l pcm you lose a small amount of power. I think someone dynoed it to be 8 hp? Not worth crying over, but enough to make ya want a special pcm, but also faster shifts with the special pcm

Click to expand...

For clarity purposes, by '2.7 PCM swap' we are refering to the "TCM" and not the "ECM" on the 98-01 cars correct? So if someone has a base 2000 3.5 300M or intrepid and puts in the 3.89 with a 2.7 TCM (and keeping the stock ECM that they have) they can solve the speedo issue but the better solution would have been to use a the TCM from a 2002 special with 3.89 compatiblity and firmer shifting and no 8hp loss, which means it's a 2002+, which means that the TCM and ECM are a single unit, which means you have to swap the wiring harnesses to do it, which means you are better off acccepting the speedo being off.

So the best options for those not wanting to completely rewire or deal with emission codes, airbag lights, etc that have a 98-01:

If you have a 2001 base 3.5 that's non PHP - Get 3.89 gears, a 2.7 TCM, and 2001 300M PHP ECM but know that the TCM will net you a power loss, so it's best to keep the stock TCM.
If you have a 98-2000 base 3.5 - Get 3.89 gears, a 2.7 TCM, and a 2000 RT ECM " " " " " " " "

^
Both options which of course are inferior to that of a 2002 Special PCM with complete wire harness swap. I assume even an 03 or 04 special PCM/wire harness swap would be superior, but if going through all that work, it makes sense to go with the best option, the 2002 special PCM.