Originally Posted by
HemiX2
This thread is for, at least, those folks that have the early (05-06) 545RFE transmission in "probably" any Chrysler platform that uses this transmission that IS NOT supported by the HP Tuner, and most likely won't ever be. With the help of one of our newer forum members, caulk04 I've done this mod. to my somewhat modified 06 5.7 Hemi Jeep Grand Cherokee Overland (see signature below). I have replaced the NGC3 PCM/TCM in the 06 with one out of an 08 5.7 Hemi Jeep equipped with an NGC4 PCM/TCM that is supported by the HPT.
It is a relatively easy swap. I picked up a used 08 Jeep PCM/TCM, P/N 05150258AC, operating system P/N 05187311AI and installed it in my 06 Jeep. I can now, after expending 2 credits, access and modify the transmission files in my 06. I have just begun to start messing with it, with caulk04's help, since he knows more about the operation of the 08 unit than I do. So far, I've made the 5 speed into a 6 speed by inserting 2P into the shift schedule (requires just a flip of a switch in the files) and have started tinkering with the rest of the up/down shift schedules, torque management settings and, hopefully, the torque converter slip settings. Once you pick up an 07-08 PCM/TCM, all that needs to be done is to install it using the FSM procedures, change the vehicle VIN and PCM odometer reading to those in your original PCM/TCM, clear a bunch of codes and, hopefully you'll be on your way.
I also have two Hemi LX's with NAG1 transmissions and, I will say that setting up the 545RFE will be a lot more difficult than with the NAG1's, because almost all the tables, histograms and item headings are considerably different and there is a lot of other stuff that I don't understand or am not familiar with. Hopefully, some folks that are more knowledgeable than I (that doesn't take much) will be able to figure them out and post them up so we can all finally get our 05-06's to work the way they should.
My thanks again to, caulk04 for giving me the huevos to attempt to this mod. Without his input, I'd still be procrastinating about whether or not I should try it and/or whether or not it would work. Let's all work together on this and maybe we can make these 545RFE's work almost as good as we can the NAG1's.