Hemi Truck Club banner

Instructions for 03 to 05 PCM Swap

26665 Views 92 Replies 23 Participants Last post by  Dan22644
Ok here is a rough draft of the PCM swap. I’ll post this for any suggestions, corrections, or added info, then edit and repost. Please feel free to give me any suggestions, I'm no pro at this, just figured I had some time to write this up, and I'm just trying to help out anyone interested in this swap. I know first hand how difficult it is trying to read through 70 pages of info trying to pick up everything you need to know.

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. These are available free, I had one guy on a facebook truck page offer to email them to me for $50, what a douche :confused:


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
See less See more
  • Like
Reactions: 1
61 - 80 of 93 Posts
Got the truck running. Ordered a pcm. No skim, 05 software with my vin to have vin match.

I have to crank for a Long time to get the truck to start and it has a ton of codes. I tripple checked all my wires in this process. I am at a loss. Super frustrated.


See less See more
High circuit typically mean open. Looks like you need to sort out wiring issues. Fix the o2 related first.
I should add I understand the EGR codes since I do not have one
Red truck, what do you think Is causing the cranking issue?
My guess would be the o2 sensor issue.. has the fuel mixture wrong. Might try holding throttle to floor while cranking. This de-fuels injectors and helps when rich..
I guess for me the write up has it vague moments. As such. On connector 1 it says
move pin 31 to 33. Okay got it
Add wire to pin 31. Got it.
Splice new wire to pin 32. ( as in splice wire to existing wire?) That's how I took it so that's what I did
I'll find my notes and get back to you..
  • Like
Reactions: 1
With out being able to read the O2 diagram I can see there is a common wire. I also re read the entire write up and read in the beginning it stated that you would be splicing into the existing wires. I double checked the actual pin out sheets and realized I should not have moved my 1/1 O2 wires since my 1/1 is already physically on the driver's side.

So I corrected all the issues. Rewired my new upstream O2 correctly and still have the weirdest issues. Have several of the same codes. When I look at live data most of it says N/A. So tomorrow I'll start ohm each sensor and see if I cooked a sensor. Hopefully I didn't cook my new pcm
If it helps make sense to someone else this is another symptom: throttle is super lazy and if the brake pedal is applied throttle goes dead.
If brake is applied and then throttle - no response
If throttle is applied and then brake(while still holding the throttle down)- rpms drop to an idle
That’s a downstream 02 sensor and plays no part in fueling at all it’s a catt monitor only. They don’t even work for about 30s after starting. Your long crank is very likely that camshaft sensor. It’s what triggers your injectors for TDC cylinder 1. If that’s not working it will default to crank sensor trigger and then start and run ok ish. Address the camshaft sensor and the APP.
Thanks for Info. I had a feeling the camshaft sensor was bad. Still need to ohm the harness to make sure. I was thinking the apps situation was due to all the other codes.
The bell crank and throttle body are only a couple months old.
Here are a couple drawings. The manual has a typo and the drawings are correct.
Handwriting Rectangle Font Wood Parallel
Handwriting Wood Font Rectangle Writing
See less See more
  • Like
Reactions: 2
Still no progress. Checked all wiring including O2s. Ohm crank, cam, map, throttle body, oil pressure switch. And pigtails. All good.
Did a continuity to ground test on all. And all good. I think the gas can and a match is up next.

*also wasted the money and replaced the cam sensor I tested that was good- no change.

Long crank to start. Lazy throttle and no throttle with brake pedal applied.

Also took off the steering wheel to make sure the clock spring wasn't shorted out.
Sounds like limp mode.. might check the electrical plugs for bent pins and fit..
Rectangle Line Font Parallel Slope
See less See more
Sounds like limp mode.. might check the electrical plugs for bent pins and fit.. View attachment 50644
Hey I just did the swap also. Motor will crank up but no throttle at all and idle is surging bad cause Ofa comp cam in it . I know I need to have it tuned but why is the bell crank apps not responding? I’m at wits end. I’ve checked and double check all wires. Any suggestions?
What codes are getting? They only changes are the additional o2s and moving the tcm wires to c-4..
What codes are getting? They only changes are the additional o2s and moving the tcm wires to c-4..
Red truck I have waiting on to answer. Lol I found the problem just a few hrs ago. Had to get a guy to come over with his big Matco scanner and we saw the apps unit was working but no signal from pcm to throttle body. We did a relearn throttle body and now it’s working great.. wish that would have been in the write up. It took a few days off my life worrying about that thing day and night..
My guess is it was a little more than a relearn. Possibly a plug not fully connected.. the TB does a calibration everytime the battery is re-connected and the ignition is turned on. You can see the throttle blade move.. But glad it sorted itself out..
Well done..
  • Like
Reactions: 1
My guess is it was a little more than a relearn. Possibly a plug not fully connected.. the TB does a calibration everytime the battery is re-connected and the ignition is turned on. You can see the throttle blade move.. But glad it sorted itself out..
Well done..
Yeah seriously all we did was a relearn. 15 minutes from opening the shop til running. Wish I had one those matco computers. But I’m so thankful for all you guys putting the info out on these pages. Lots of research and hrs in this thing.
  • Like
Reactions: 1
61 - 80 of 93 Posts