Been having some trouble with my 03 hemi, took it to the shop and got it fixed but they said they were having problems with my computer also, I've heard of people swapping the junk 03 computer for the much better 05 computer, just trying to figure out what needs to be done to make this swap happen!

 

If you replace the computer on an 03, you need to change the full wireing harness and some connectors.
Our 03's have a seperate transmission controller that later engines don't have. After 03, the engine and transmission computers are integrated into one.
Changing it all over on an 03 is doable, but a lot of hard work. It's really not straight forward from reading the threads of guys that have done it.
Al.

 

Yup. You either do a complete 05 harness/PCM swap or adapt your 03 harness to the 05 PCM. Either way it isn't a bolt in.

 

You'll prob need a new odometer as well. The connectors may be the same, but their internal functions slightly differ. Mileage is stored in the odometer!

 

It's not a hard swap , pretty much plug and play.. 03 motors don't have egr valve , so you'll have a plug that don't go to anything..You won't have to change the engine harness on top of the motor..Injectors , coils etc.. There are two plugs behind the motor that plugs into.. I think if you go through with it , you'll be glad you did..

 

Odometer is the same..

 

Ever done this? Or seen It done? I could use a walk through if you know enough about it, I'm pretty excited to get this project goin

 

It's possible, but it's a decent project. You either:
- replace all of the wiring in the engine compartment (although you can plug into the current injector harness), all the way around the headlights to the connectors inside the cab, fuse box, etc with the 2005 counterpart.
- Or make a custom harness out of a 2003 harness. You basically remove your TCM from the equation and route those wires to the PCM instead. You then have to add wires for 2 more O2 sensors and wire them to the current ones, etc. Your odometer will be fine, as well as your throttle body and APPS. The existing O2 sensors are different so keep that in mind if you use another harness.

You'll have 2 egr codes unless you get it custom tuned out. Also, if you're 4x4, you'll lose your 4x4 cluster light without some serious mods

The 2004/2005 PCM is better for tuning if you are putting in an aggressive camshaft. It also gives you some more transmission tuning options when tuning yourself, but probably not worth it if you're not doing a cam or something like that.