Instructions to change an 03 Hemi PCM to an 05

[finally03gt]

Seems likely. If I do the swap, I'll just make sure to follow the pinouts on that circuit and be sure everything has a home.

Thanks again for all the info.

 

[HemiLonestar]

There are links for the factory service and parts manuals from 02-06, you should be able to find everything you need [emoji106]

Sent from my HTC U11 using Tapatalk

 

[Redtruck-VA]

The method I use is to use a electricians label booklet of numbers. Have a notebook and list the wires according to the 05 c4 plug pin-out. 1-28... then cut the 03 TCM plug off the wire harness. Then match the describtion/color from the TCM pin-out to the 05 c4 pin-out and number it (1-28) accordingly. Identify and label all the 05 c4 plug (salvage yard) wires. Along with all of the TCM harnes wires. At this point all wires should have a matching number or a home. There are something like 6 wires that are for the O2s that is added. I'm doing this from memory so bare with me if I miss a wire. But you will identify it during the process. Three of these wires will go to a common ground (firewall). Two will plug into empty pin holes in c2/c3 and one wire will splice to existing wire. So now you will have c4 plug with it's wires hanging from it all with numbers attached to each wire. And the original 03 TCM harness with its plug removed and each wire with an identifying number. Double check that all wires are identified. Final step, solder matching numbered wires together..
In itself the 05 pcm has more accurate tuning allowing for better performance and street manners. Now with all that said I used a modified 03 pcm successfully with 6psi boost. It was quirky at times but pretty steady. Believe it ran in the mid 12's.

 

[chrisp2493]

When doing the oxegyn sensors, bank 1 has to be driver side, bank 2 has to be passenger side. If these are switched around, your truck won’t run right. It depends on what exhaust setup you have (stock or modified/cats eliminated). So you may need to repin the wires that are already in the pcm for the existing sensor if it’s on the passenger side to begin with


I Bleed Ram Trucks

 

[finally03gt]

I am consistently amazed at the wealth of knowledge that is found in Forum boards. Thank you guys for all the direction. It doesn't seem like a task for the faint of heart or those scared of wiring. But it sounds manageable with the information you guys are giving. again great resource!

 

[Redtruck-VA]

I seem to remember a typo on the pin-out where the plug number is called out wrong. Something like c1-32 is called out twice where as one of them is actually c2-32 . Chris has done his swap more recently than I did mine so he probably recalls it better than I. I swapped mine july 2015... here it is...

 

[mairj40]

Dumb question. There seems to be a few pin numbers from the 2003 TCM that are not accounted for in the 2005 plugs. Do those just stay connected to the TCM?

 

[HemiLonestar]

You don't keep the TCM if you are converting to the 05 PCM (TCM function is integrated).

 

[Redtruck-VA]

Correct the 03 TCM is removed. Need to identify the extra wires. My conversion was a manual 05 pcm with no TCM related wiring. But I seem to recall there was a couple extra APPS wires. Identify the extra wires pin numbers and we can figure it out.

 

[mairj40]

You don't keep the TCM if you are converting to the 05 PCM (TCM function is integrated).

I'm confused, or missing something then. Based on the images attached at the beginning there are several TCM pins not accounted for.

2 #6 pins for RPM signal and Crankshaft position sensor.

Pin 8 - fused ignition switch output
Pin10 - TMR
Pin 11 - Fused ignition switch output
2 #12 pins for APPS output #1 and TPS
2 #28 pins for vehicle speed signal
Pin 39 - Ground
Pin 41 - TRS sense (C1)
pin 43 - PCI bus
Pin 45 - TPS #1 output
2 #51 pins sensor grounds
pin 56 - Fused

These are not accounted for in the directions. Where would they need to go?

 

[Redtruck-VA]

Maybe Chris knows this off the top of his head. I'll have to research but can't do it now.

 

[chrisp2493]

Any pins that do not have a specified place to go into the new 05 pcm, just get taped up and abandoned


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[mairj40]

Another dumb question.

How do you know which wires on the new O2 sensors are which? My adapters have 4 white wires.

 

[Redtruck-VA]

Another dumb question.

How do you know which wires on the new O2 sensors are which? My adapters have 4 white wires.

The plug should be numbered 1-4.
1-c2-17
2-grd
3-c1-32
4-c2-33

 

[mairj40]

The plug should be numbered 1-4.
1-c2-17
2-grd
3-c1-32
4-c2-33

Is this the upstream or downstream sensor?

 

[Redtruck-VA]

Is this the upstream or downstream sensor?

Up stream
..

 

[Oneslowram03]

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

 

[Oneslowram03]

Would any 05 pcm be compatible on my 03 Dodge Ram ?

 

[Redtruck-VA]

Would any 05 pcm be compatible on my 03 Dodge Ram ?

Is your truck skim active? Most 03's are not and alot of 05's are. So if you are using a used 05 pcm. You need to know the pcm status.

 

[Oneslowram03]

Is your truck skim active? Most 03's are not and alot of 05's are. So if you are using a used 05 pcm. You need to know the pcm status.

I think it’s a skim I have a grey key