Eco Diesel frame / body swap challenge. Small issue...

[Hemi drifter]

I've taken on swapping the cab and box from one truck to another. Here’s the backstory. 3 years ago I bought a beautiful 2016 Ram Eco diesel LIMITED with 115,000km. Very (very) shortly after buying it the motor blew. Private sale and not the sellers fault, but effing sucked. Took the engine out and brought it to a guy to rebuild it... and he screwed me over and disappeared with my engine, Number disconnected everything. So long story short I've had this $30K paper weight in my driveway for over two years with no engine and missing a bunch of wiring, the turbo, etc etc.. At long last I found a donor truck. Hallelujah! Same frame config (4x4 crew cab short box) but lower trim level and body is beat up. I got it for 8k so I jumped on it. My plan was/is take the body and box off the limited and throw them onto the donor frame with running engine. I completed 95% of the swap tonight (just missing the box). I connected the battery and everything came to life as expected. Turned it on and it fired right up!! BUT...it shuts off after two seconds. It did that a few times and now wont even turn over. I know the battery in my fob is weak so I'll change that in the morning , and I also intend to purchase Alpha OBD to see what I can see and reconfigure there... but I'm stumped as to what the reason might be that it's doing this. Almost feels like a safety feature, like anti theft maybe, but not sure. I do have one harness block coming out of the cab and it has no mate coming from the frame, so that might be an issue, but I also suspect that it's for the air suspension which the donor frame does not have (I could be wrong, but would make sense). I scanned it and got 3 codes of note:
U0001 CAN C Bus
P26A6 Engine coolant Bypass Valve Sensor circuit low
P0513-00 Invalid SKIM Key

The fob I used to start the truck is the one that goes with that cab. The ECM is the one that matches with the donor engine as it has been tuned (EGR / DPF Delete and Stage 2 tune) .
I'm bummed because I'm soooo close to having this truck back on the road after 2+ very long years! Has anyone done this before? Anyone here work at a dealership and have any idea of what it could be?
I don't have a picture unfortunately of the lone connector, but it's grey fairly big and square with about 14 wires going into it and it comes out of the cab at the back of the driver front fender.
Thanks in advance to anyone who can help shed some light on the subject

 

[GTyankee]

You did not mention if the replacement engine is also a Ecodiesel
Stage 2 i think they call it

i don't think that there was a Stage 1 Ecodiesel put in Ram trucks

You may find that you will need the VIN for both the Trucks Body & the vehicle that the ECU came out of

The ECU, the Radio & Ignition & WIN module have to match up
something about the PIN
to get PINs, you need the VINs

If i recall correctly, all PIN are the same, when a vehicle leaves the Assembly Line
Unless someone requests that the PIN be changed/reset, they should still have the factory setting

 

[crash68]

The fob I used to start the truck is the one that goes with that cab. The ECM is the one that matches with the donor engine as it has been tuned

More than like the VIN number in the ECM doesn't match the rest of the truck, you should be able to change that with AlfaOBD. You shouldn't loose the tune in the ECM, people on another forum have done this many times buying used ECM that were tuned and needed to change the VIN and injector codes. Being the ECM was tuned with the engine, the injector codes don't need to be changed in your case.

 

[04fxdwgi]

@crash68 beat me while I was typing. LOL

Question, what year is the donor? I as because the communication protocalls (Can Bus) changed between some years.

The U0001 (CAN C Bus, which can be a disconnected module or broken / disconnected wire) and P0513-00 (invalid SKIM - security ignition key module) would both stop from running if the keys and VIN numbers don't all match.
The ECM and security ones do need to match, but can be fairly easily be changed. ECM will keep old one in there, too.
Don't forget, that almost every module in these trucks have VIN attached to them, like steering and ABS, and so on.

Probably correct on the missing harness connector (air system), but be sure to delete that air system in AlfaOBD, as it missing will make your system harass you later on with warnings and such.

 

[crash68]

Question, what year is the donor? I as because the communication protocalls (Can Bus) changed between some years.

I don't think any of the comm protocols have changed amongst the DS EcoDiesels but the wiring harnesses changed. I believe '16 was the first year for the DEF quality sensor. Depending on who tuned the OPs ECM, that may cause an issue depending on how the tuner disabled the diesel emissions.

 

[Sandevino]

Assuming the engine is the same version (gen 2) change the VIN in the ECU and try again.

 

[Hemi drifter]

@crash68 beat me while I was typing. LOL

Question, what year is the donor? I as because the communication protocalls (Can Bus) changed between some years.

The U0001 (CAN C Bus, which can be a disconnected module or broken / disconnected wire) and P0513-00 (invalid SKIM - security ignition key module) would both stop from running if the keys and VIN numbers don't all match.
The ECM and security ones do need to match, but can be fairly easily be changed. ECM will keep old one in there, too.
Don't forget, that almost every module in these trucks have VIN attached to them, like steering and ABS, and so on.

Probably correct on the missing harness connector (air system), but be sure to delete that air system in AlfaOBD, as it missing will make your system harass you later on with warnings and such.

They're both 2016, which is one of the reasons I feel the swap should be successful. I put a new battery in the fob and will try to swap the vin number in the ecm shortly if alpha OBD has that capacity. I'll also tune out the air suspension to try and hopefully eliminate that can bus code. Thanks for all the tips everyone! I'll report back on how it goes.

 

[Hemi drifter]

Hmm... so I can't get Alpha OBD to connect. I have the suggested interface cable (obdlink ex) for my vehicle, and a windows laptop. When I click on the "connect" button, nothing happens. It flickers for a second, then still says "connect", whereas I'm assuming it would say "disconnect" if it had connected. I found where to change the VIN in the ECM and everything, but can't get the damn connection to work. Both trucks are 2016 so I don't think I need the gateway bypass module either. Not sure what I'm doing wrong :/

 

[04fxdwgi]

Interesting. I use the MX+ (WiFi) and windows 10 laptop and had zero problems connecting on my '16.

Correct that the '16 doesn't need the bypass. That's for '18 and up

You use these settings?



These are the settings in the advanced mode page:

 

[crash68]

so I can't get Alpha OBD to connect. I have the suggested interface cable

Can you connect to other modules like the BCM? Have you connected to your truck before? You could try plugging the ECM from the original engine in to see if that talks.

 

[Hemi drifter]

Update: For whatever reason the damn cable I bought (OBDLink Ex) never did work with either the laptop or my phone. The light would come on but stay red so not sure if maybe mine is defective or what, but I got fed up and bought the OBDLink MX+ which uses Bluetooth, and that one connected to my phone right away. After a few tries (turns out letters have to be lower case) I was able to change the VIN Number in the ECM, and she fired right up! GREAT SUCCESS (in a Borat voice)! So the swap is 90% a success, but I still have a few things to figure out. I have a big Canbus connector (14 wires) on the driver side front fender well coming from the cab, that has no counterpart on the frame :/ I thought it was for the air suspension, but the error code I'm getting says transmission, so I'll have to dig into that. Fortunately I still have the other wiring harness if need be but I'm hoping I don't have to swap the whole harness out. The truck drives nicely in all gears, so I think it must be for the transfer case perhaps. The donor truck was an outdoorsman with the BW 44-45 transfer case (no auto 4wd) and the other has the BW 44-44. I did swap out the transfer cases in an effort to avoid any error codes and maintain the auto 4wd functionality, but it would appear I have a little more work ahead of me. The last thing I'll need to figure out is the Air suspension "delete" programming side of things. It's my understanding that I can program it out using AlphaOBD, but so far I can't figure out how, with my phone at least. Haven't tried with the laptop yet. Other small details would be the rear tail light sockets (LED vs non LED), and rear dual exhaust, but I don't think I'll bother switching the bumper and exhaust.
So yeah, a little more fussing around, then I can detail her and move onto the next project.

​

 

[crash68]

The last thing I'll need to figure out is the Air suspension "delete" programming side of things. It's my understanding that I can program it out using AlphaOBD, but so far I can't figure out how, with my phone at least.

From the "Known Working List" in the AlfaOBD thread:

P/T Chassis Net-ASCM Air Suspension Control Module = not present

As for the transfer case, search the forum for BW44-44 to BW44-45 swap, people have posted what needs to be adjusted for each transfer case.