03 to 05 PCM swap

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
Well I'm gonna start this swap. After a few weeks of searching I ordered (what I sure hope lol) is the right pcm from a junkyard in Texas. Found some extra plugs at a local scrapyard. Definitely nervous about doing this, hope everything goes smoothly 37fa9894aad75d2ef4248a4b2d4f184d.jpg
 

HemiLonestar

Senior Member
Military
Joined
Jun 1, 2012
Posts
5,991
Reaction score
2,952
Location
MD
Ram Year
2016
Engine
5.7 hemi
Well I'm gonna start this swap. After a few weeks of searching I ordered (what I sure hope lol) is the right pcm from a junkyard in Texas. Found some extra plugs at a local scrapyard. Definitely nervous about doing this, hope everything goes smoothly 37fa9894aad75d2ef4248a4b2d4f184d.jpg
If you're that nervous about it, hotwireauto has already done these harness modifications successfully.

Sent from my HTC One_M8 using Tapatalk
 

CanadianHemi

Member
Joined
Jan 15, 2016
Posts
88
Reaction score
72
Location
Nova Scotia
Ram Year
2005
Engine
5.7L Hemi
Stupid question, what exactly does this do? Is this a beneficial mod of some sort? Or do you just need a new standard PCM? I put a new PCM in my truck and everything was fine?
 

HemiLonestar

Senior Member
Military
Joined
Jun 1, 2012
Posts
5,991
Reaction score
2,952
Location
MD
Ram Year
2016
Engine
5.7 hemi
Stupid question, what exactly does this do? Is this a beneficial mod of some sort? Or do you just need a new standard PCM? I put a new PCM in my truck and everything was fine?
Going from an 03 to 05 PCM allows the ability to properly custom tune the engine for a cam swap as well as tune the trans

Sent from my HTC One_M8 using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
If you're that nervous about it, hotwireauto has already done these harness modifications successfully.

Sent from my HTC One_M8 using Tapatalk



I'm not nervous about the wiring (I'm an electrician by trade) and I got all the wires matched from the pinouts. I'm just nervous about potential vin mismatches and getting my tuner to recognize everything once I finish. It's my daily so I don't want to be out of a truck for a week waiting on stuff. We'll see I guess
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
Stupid question, what exactly does this do? Is this a beneficial mod of some sort? Or do you just need a new standard PCM? I put a new PCM in my truck and everything was fine?



Yeah you're lucky to start out with the good truck year. I'm just adapting to run a bigger cam this summer
 

HemiLonestar

Senior Member
Military
Joined
Jun 1, 2012
Posts
5,991
Reaction score
2,952
Location
MD
Ram Year
2016
Engine
5.7 hemi
I'm not nervous about the wiring (I'm an electrician by trade) and I got all the wires matched from the pinouts. I'm just nervous about potential vin mismatches and getting my tuner to recognize everything once I finish. It's my daily so I don't want to be out of a truck for a week waiting on stuff. We'll see I guess
Matching everything right, the pcm programming and converting the coil pack connectors to the newer style is why I have been seriously considering sending it to them. They actually take your 03 harness and alter it, plus program the pcm.

Sent from my HTC One_M8 using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
What's the benefit of changing the coil packs? Wait...don't tell me...I'll spend more money haha
 

HemiLonestar

Senior Member
Military
Joined
Jun 1, 2012
Posts
5,991
Reaction score
2,952
Location
MD
Ram Year
2016
Engine
5.7 hemi
What's the benefit of changing the coil packs? Wait...don't tell me...I'll spend more money haha
Cleans up the engine bay, gets rid of the single coils and wires and allows use of the dual coil setup 06+ use

Sent from my HTC One_M8 using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
This is a dumb question. Is an aftermarket air fuel sensor different then the upstream o2 sensor? I was considering getting a wideband a/f for future tuning, but I already have to buy two more o2 sensors to wire in with the 05 pcm
 

Ajwalk2008

Senior Member
Joined
Jan 14, 2016
Posts
411
Reaction score
92
Location
Springfield, il
Ram Year
2005
Engine
Hemi 5.7
This is a dumb question. Is an aftermarket air fuel sensor different then the upstream o2 sensor? I was considering getting a wideband a/f for future tuning, but I already have to buy two more o2 sensors to wire in with the 05 pcm



Our trucks use narrow band o2 sensors the wideband o2 sensors have to have a gauge or separate module. If you get a custom tune you won't need the rear o2 sensors that the 2005 pcm wants to see


Sent from my iPhone using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
I won't need to downstream 02's, I'll tune them out, but I was told to wire the upstream in on the drivers side. I already have a **** in my header collector, I just have to run the wire
 

jotin

Senior Member
Joined
Jun 7, 2016
Posts
428
Reaction score
190
Location
your mom
Ram Year
2003
Engine
5.7
Pain in the butt even as an electrical tech for dodge. But the BEST thing I did for my 03 Ram. Hit me up if you need any guidance. Remember one of the transmission sensors requires a 5v reference. I just shared it with the cam shaft position sensor 5v and spliced it in. That was the only thing I ended up having to go back in and do.


Sent from my iPhone using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
So I think I'm gonna do it right and send the pcm to B&G performance to have the vin flashed. Costs $130. Is this absolutely necessary? I keep hearing both ways. Any other places you know of?
 

jotin

Senior Member
Joined
Jun 7, 2016
Posts
428
Reaction score
190
Location
your mom
Ram Year
2003
Engine
5.7
So I think I'm gonna do it right and send the pcm to B&G performance to have the vin flashed. Costs $130. Is this absolutely necessary? I keep hearing both ways. Any other places you know of?



No necessary. I wouldn't personally waste the money. You don't have a SKIM module so your truck isn't gonna care one way or the other. You can PM me if you'd like if you need help at all. I did it a few months ago myself. I'm a dodge tech , so I've got diagrams and diagnostics and whatnot if you need assistance


Sent from my iPhone using Tapatalk
 
OP
OP
chrisp2493

chrisp2493

Always Modding
Joined
Oct 30, 2016
Posts
3,006
Reaction score
1,870
Location
Warren, OH
Ram Year
2003
Engine
392 Hemi
Plugged in the new pcm and the truck started right up. @jotin was correct about the skim not doing anything.
 
Top