Instructions to change an 03 Hemi PCM to an 05

[chrisp2493]

I have this posted on another forum so I'll add it here as well. This is a great mod to do to gain transmission tuning and much better tuning for big mods such as cams/boost/strokers/etc....I have done this on my own truck and have very few issues.

I have scans of all the pinouts and diagrams on my computer. I will upload them to this post, but I've noticed the pictures on here don't always show up the greatest. I found all of them in the 03 and 05 service manuals. Here is a website to download the 05 Service Manual. I Found the 03 stickied somewhere else. If you can't find them anywhere else, PM me and I will email you all my scans.

General overview
You will need to add in a new bank of oxygen sensors, Upstream and Downstream. Add wiring from the new sensors all the way to the computer location and pin it to the connectors. You will add 6 new pins, and two wires will splice onto existing wires for a return signal.
Remove the old TCM computer from the truck. Most of these wires will be pinned onto connector C4 on the 05 PCM.
You will need to purchase a NGC connector (C4 Green) with pins. I believe you can order these online, or just go to a salvage yard and cut off a connector or two to use. The pins will come out fairly easily. Pry open the 4 tabs on the connector to remove the back, then use a flat screwdriver to unlock a red holding tab on the side of the connector. Then the pins should pull out with a good tug. The pins can be reinserted, then the red tab closed to lock the pins in solid. It may be beneficial to purchase a few extra connectors, the cover on the back of the plug has a tendency to break very easily.

Downstream sensors can be tuned out with a custom tune to remove any codes if you are not installing catalytic converters. It's recommended to add the wiring and sensors, but is not absolutely necessary in order to work.

O2 sensors-
05 sensor designatons
Sensor 1/1 Driver side upstream
Senor 1/2 Driver side downstream
Sensor 2/1 Passenger side upstream
Senor 2/2 Passenger side downstream

For adding in the new O2 sensors, the 03 truck should have the 1/1 and 1/2 sensors located on the passenger side. On the new 05 setup, Bank 1 will be the driver side; Bank 2 will be the passenger side. On my personal truck, having these reversed caused major issues with the truck running right. I had to switch pins, so my new sensors went to Bank 1 pins, and I had to relocate the existing sensors to the open spots for Bank 2.


Word of caution, it is not recommended to cut the harness off of the new sensor. The sensor wires are typically silver or aluminum, and shouldn’t be soldered to copper. I used Casper Electronics O2 sensor extenders for the connectors; I cut them off and soldered them to the new wire going to the computer.

Connector C1
Switch Pin 31 to 33
Add new Downstream o2 signal wire to pin 31
Splice on new Upstream o2 Return to Pin 32
Add TCM Pin 46 to Pin 26 SCI Receive (TCM)
Add TCM Pin 7 to C1 37 SCI Transmit (TCM)
Add TCM Pin 38 to C1 27 5 Volt Supply

Connector C2
Switch Pin 18 to 17
Add new upstream o2 Heater Control to Pin 18
Switch Pin 31 to 33
Add new upstream o2 Signal
Splice on new Downstream o2 Return to Pin 32

Connector C3
Switch Pin 9 to 10
Add new o2 downstream heater control to Pin 9

Connector C4
TCM Pin 60 (OD solenoid Control) to Pin 1
TCM Pin 59 (4C Solenoid Control) to Pin 2
TCM Pin 40 (MS Solenoid Control) to Pin 4
TCM Pin 19 (2C Solenoid Control) to pin 6
TCM Pin 55 (UD Solenoid Control) to pin 8
TCM Pin 20 (L/R Solenoid Control) to pin 10
TCM Pin 18 (Pressure Control Solenoid Control) to Pin 11
TCM Pin 37 (Ground) to Pin 12
TCM Pin 53 (Ground) to Pin 13
TCM Pin 57 (Ground) to Pin 14
TCM Pin 1 (TRS T1 Sense) to Pin 15
TCM Pin 3 (TRS T3 Sense) to Pin 16
TCM Pin 49 (Tow/Haul Overdrive Off Switch Sense) to Pin 17
TCM Pin 15 (Transmission Control Relay Control) to Pin 18
TCM Pin 16 (Transmission Control Relay Output) to Pin 19
TCM Pin 48 (4C Pressure Switch Sense) to Pin 20
TCM Pin 29 (UD Pressure Switch Sense) to Pin 21
TCM Pin 9 (OD Pressure Switch Sense) to Pin 22
TCM Pin 2 (TRS T2 Sense) to Pin 26
TCM Pin 17 (Transmission Control Relay Output) to Pin 28
TCM Pin 50 (L/R Pressure Switch Sense to Pin 29
TCM Pin 47 (2C Pressure Switch Sense) to Pin 30
TCM Pin 30 (Line Pressure Sensor Signal) to Pin 31
TCM Pin 14 (Output Speed Sensor Signal) to Pin 32
TCM Pin 52 (Input Speed Sensor Signal) to Pin 33
TCM Pin 13 (Speed Sensor Ground) to Pin 34
TCM Pin 54 (Transmission Temperature Sensor Signal) to Pin 35
TCM Pin 42 (TRS T42 Sensor) to Pin 37
TCM Pin 36 (Transmission Control Relay Output) to Pin 38

 

[chrisp2493]

Here are the 2003 pcm pinouts along with the Transmission Control Module (TCM)
C1 by Chris Pearce, on Flickr
C2 by Chris Pearce, on Flickr
C3 by Chris Pearce, on Flickr
C4 by Chris Pearce, on Flickr
TCM 1 by Chris Pearce, on Flickr
TCM 2 by Chris Pearce, on Flickr

 

[chrisp2493]

Here are the 2005 PCM pinouts

05 C1 by Chris Pearce, on Flickr
05 C2 by Chris Pearce, on Flickr
05 C3 by Chris Pearce, on Flickr
05 C4 by Chris Pearce, on Flickr

 

[chrisp2493]

And the Standard oxygen sensor diagram.
O2 Wire Diagram by Chris Pearce, on Flickr


If you decide to also wire the rear o2s you will find a typo on the schematic showing the return wire to pcm listed as c1-32 (same as front). It should read c2-32 (rear).

 

[chrisp2493]

And in case the pictures disappear years later, here is a link to the photo album they are in
https://www.flickr.com/photos/159420730@N03/albums/72157662374612628

 

[mwclarksr]

Downstream sensors can be tuned out with a custom tune to remove any codes if you are not installing catalytic converters. It's recommended to add the wiring and sensors, but is not absolutely necessary in order to work.

What if I don't want to add the 2nd Cat?

I don't mind keeping my 1 Cat, I just don't want the extra cost on a 2nd one.

 

[chrisp2493]

What if I don't want to add the 2nd Cat?

I don't mind keeping my 1 Cat, I just don't want the extra cost on a 2nd one.

That I’m not 100% on, I have had my cats removed for awhile now. The main concern is the upstream oxegyn sensor, that is necessary for the pcm but having the cat there or not won’t effect anything.


I Bleed Ram Trucks

 

[chrisp2493]

I believe the 03 has the cat after the y pipe, and I think the 04 and up have a cat on each side just after the headers


I Bleed Ram Trucks

 

[mwclarksr]

I believe the 03 has the cat after the y pipe, and I think the 04 and up have a cat on each side just after the headers


I Bleed Ram Trucks

That is true on the '02-'03. Single Cat after Y. I suck a soldering, hands shake too much. I know you linked the FSM on my thread, I'll link the thread here if they want the FSMs. If that is alright with you. I'm not trying to hijack your thread.

http://www.ramforum.com/threads/3rd-gen-parts-manuals-and-2003-2004-service-manuals.6504/

 

[chrisp2493]

That’s fine, you can link them here. Only problem is they don’t have the 05 manual in there. I found it on another Hemi website but can’t remember where, I have it and can email the pdf to anyone that’s interested


I Bleed Ram Trucks

 

[mwclarksr]

That’s fine, you can link them here. Only problem is they don’t have the 05 manual in there. I found it on another Hemi website but can’t remember where, I have it and can email the pdf to anyone that’s interested


I Bleed Ram Trucks

Actually, on that same thread, HemiLonestar linked the '02 -' 08 FSM.

Different question, do you think I could do the same changes to the pins by using a 4.7 harness and adding the pins to make the '05 Hemi work?

 

[chrisp2493]

Actually, on that same thread, HemiLonestar linked the '02 -' 08 FSM.

Different question, do you think I could do the same changes to the pins by using a 4.7 harness and adding the pins to make the '05 Hemi work?

I don’t know very much about the 4.7 harness but from watching everyone else do the conversion I think you definitely want to start out with the Hemi harness. I think there is a lot that is different and the conversion is already somewhat hard enough to get done


I Bleed Ram Trucks

 

[mwclarksr]

What I need to do is look over the Schematics and find the Differences and Similarities. One of the junkyards I go to has a couple of '04 harness'. If I could, I would go get one today, but I'm supposed to lay off buying things as told to me by my wife.

 

[Redtruck-VA]

When I did mine I printed out both the 03 pin-out and the 05 pin-out at the same scale and taped them side by side line by line. It made the wiring very clear to me and easy to understand. Chris by far has the best information on doing this swap. IMO, any 03 that is going to be modded needs it's 03 pcm swapped as the first mod.

 

[chrisp2493]

One more thing, there’s a guy trying to do this swap in California right now and said he’s having a ton of issues with getting it to pass smog testing, he even went the extra mile and got his 03 vin professionally flashed to the 05 computer. So if you have heavy emissions testing in your area that will be an issues. This swap is pretty necessary for doing big mods, so there will be some drawbacks to deal with on emissions. Luckily for me I have zero emissions testing to go through.


I Bleed Ram Trucks

 

[mwclarksr]

One more thing, there’s a guy trying to do this swap in California right now and said he’s having a ton of issues with getting it to pass smog testing, he even went the extra mile and got his 03 vin professionally flashed to the 05 computer. So if you have heavy emissions testing in your area that will be an issues. This swap is pretty necessary for doing big mods, so there will be some drawbacks to deal with on emissions. Luckily for me I have zero emissions testing to go through.


I Bleed Ram Trucks

Indiana got rid of standards back in the late '70s. Too many people could pay off shops to get an approval sticker. In most aspects, it's great that it's gone. But, what types of vehicles I've seen on the road, missing headlights replaced with small driving lights, caved in front or rear end (like they hit a pole or tree), things like that. I wish some kind of inspection was put back in, but emissions shouldn't be one of them.

To me, those emission standards boil down to the payment from fines given to the individual from the local and state level. To them, environment is secondary. But, this is where I will stop this post, I will not turn this into a debate on the government, too much, as there is, already.

 

[mwclarksr]

Alright, to answer my own question regarding the usage of the 4.7 harness, can't be done without HEAVY MODIFICATION to the harness. The 3 connectors on the 4.7 harness only hold 32 pins, the '03 to at least '05 are a different shape and hold 38 pins. Now, before I get remarks about the same connectors for 3.7, 4.7, 5.7, I was thinking on using my '02 4.7 harness for the pin re-arrangement. '02 is the only year that has a different shape when it comes to the 3.7/4.7 & 5.9 (360 Gasser).

So I will repeat this: If anyone that has a '02 3.7, 4.7 or 5.9, you cannot use the '02 harness as a base to re-pin for a Hemi. Go ahead and start with an '04 if you can get one. The colors, on the connectors, will be different (speaking as if you have an '03). So keep that in mind as well.

 

[mwclarksr]

Here is another question: While looking at the pin layout differences between the '03 & '05, how do you account for the differences in the first 38 pins on C1? ('03 connector is a 38 pin while the '05 connector is a 60)

Example:
'03 C1 Pin 1 = Coil Control No. 8

'05 C1 Pin 1 = Wastegate Solenoid Control

Wouldn't every pin on an '03 (and '04, because while looking at it briefly, they are the same harness), before adding the extra pins, need to match in order to use the '05 ECM?

 

[chrisp2493]

Here is another question: While looking at the pin layout differences between the '03 & '05, how do you account for the differences in the first 38 pins on C1? ('03 connector is a 38 pin while the '05 connector is a 60)

Example:
'03 C1 Pin 1 = Coil Control No. 8

'05 C1 Pin 1 = Wastegate Solenoid Control

Wouldn't every pin on an '03 (and '04, because while looking at it briefly, they are the same harness), before adding the extra pins, need to match in order to use the '05 ECM?

I think you are looking at the wrong connectors. Look at the pictures I posted and the first 3 plugs are almost exactly identical. And since you said wastegate solenoid control I think you might be looking at the cummins computer


I Bleed Ram Trucks

 

[mwclarksr]

Hmmm, I could have sworn that I was looking at the NGC connector.II'll look when I get home from work.

I just bought a used '04 Hemi PCM for $58 shipped on eBay.