downgrading JT 2022 GPEC5 EMC/Harness hardware to GPEC2a?

[Ram]

Hello all,

I'm new to the forum and would really appreciate it if you could help me with much-needed information.

My goal: install Prodigy Turbo Kit for my Jeep JT Gladiator 3.6L 2022.

The problem: ECM GPEC5 has no unlocking solution, and from my email exchanges with HPTuner, it's unclear when or if an unlocked version will be available.

My question is: a workaround solution of replacing the ECM GPEC5 to GPEC2a and the engine wiring harness from an early Gladiator 2021 could solve that?

I've found more than a few used Gladiator's GPEC2a for sale, and some harnesses (not sure which is the correct part number, I'll dive deep into it if I know for sure this workaround is, well, workable)

Does anyone have any experience with downgrading the EMC/Harness hardware? is it doable? is there anything else I need to take into account that I'm missing at the moment?

Many thanks in advance for any thought/advice/tip that could help me install the kit on my beloved Gladiator!
Cheers to all!
Best,
Ram

[rays04gtx]

some of it will depend on local emission laws.

[Ram]

@rays04gtx thank you for your reply!

assuming there's no emission law limitation; using an ECM and the engine wiring harness from an early JT 2021 is fully compatible with the JT 2022? all connectors and such? other than that there's anything else I need to be aware of?

[Ram]

for anyone who's looking at this thread, the following is a reply I've received from a different forum:

So your jeep has a body control module, transmission control module, if it is automatic, entertainment radio, havac panel, evic, shifter and steering wheel controls. They all have a rolling security address, that is expected to be set at start up. If one returns a wring address the jeep goes into security lock down.

If you load an older ECM with the wrong VIN this will also cause a lock down. I have not found d a way outside of chrysler to overwrite a VIN.

[rays04gtx]

From what I've seen ,

I have an associate who's done it a few times , one was a 2014 Ram that him and his nephew installed ECM from a 2010M6 5.7 Challenger, they changed the dash and did have some issues at 1st but got it all worked out,the others went the other way, installing everything or most everything in to older Rams 02-05s he was telling me the 2014 was the best option , he's done three 2002s with the 2014 set up a few 05's and four 04's tried once with an unlocked 2016 Ram 1500 system into a 03 ram, and that was a nightmare, pulled it all back out and used a 2009 ECM and wiring.. as for LX platform , a pair of 06 Magnums that they switched systems out for 2012 Challenger M6 systems, so they could install SRT392/T56 Magnums drivline.
I asked him last night , and he said pre 15 systems are not all locked in sync.

If your going to do this, 1st you'll have to seen if the Vin can be programed in to the 21 and older system, if it can then you'll need everything that would throw a security code.

[Ram]

1st you'll have to seen if the Vin can be programed in to the 21 and older system

Yup, that is defiantly the biggest hurdle, I wish HPTuner would look into this kind of solution in addition to their attempts to unlock the GPEC5.

Thanks much for your input!!

[N2speed]

I can add a VIn to any Gpec2 PCM, have not tried the Gpec5 yet. HP Tuners has never offered Vin changes on any year Dodge. So I wouldn't wait for that.

[Ram]

I can add a VIn to any Gpec2 PCM

Hi, I just saw your message; that is great to know! from your experience, would it be possible to replace the ECM to the GPEC2 (with the updated VIN) for the 2022 Gladiator?

[N2speed]

Never tried it. So not sure.

[Ram]

Never tried it. So not sure.

understood.

some ELI5 questions, if you will, assuming the VIN was written into the used GPEC2a:

1. should the GPEC2a be a cloned version of my original GPEC5 for it to work?
2. when flashing the ECM, it doesn't write over the VIN, is that correct?
3. besides the VIN (and I'm guessing millage), what other info would you recommend writing into the ECM?
4. do you have a GPEC2a ECM?

thanks a million!

[N2speed]

understood.

some ELI5 questions, if you will, assuming the VIN was written into the used GPEC2a:

1. should the GPEC2a be a cloned version of my original GPEC5 for it to work? No It would have its own info.
2. when flashing the ECM, it doesn't write over the VIN, is that correct? No it does not write over the vin. VIN is programed separately
3. besides the VIN (and I'm guessing millage), what other info would you recommend writing into the ECM? Only other info it would need would be the 4 digit security code from the dealer. PCM will have to be installed for that to work. May have another idea that might work though.
4. do you have a GPEC2a ECM? Not sure if I have one for a TRX would have to check in the AM.

thanks a million!

See above ^^

[N2speed]

Did some research on Gpec5 everything is different. There is no way to swap to a Gepec2a cheaply.

[Ram]

See above ^^

thank you for clearing this up for me!

4 digit security code from the dealer

that's a new hurdle, is that code unique for each dealer? What if we were using a known dealer code that isn't mine?

[Ram]

There is no way to swap to a Gepec2a cheaply.

I know the wiring harness should be replaced to fit the GPEC2a ECM. Is there anything else?
can you pls give a ballpark guess for the swap cost?

currently, I'm in contact with Fiat's Customer Care STELLANTIS EMEA (the company that owns Jeep), asking them to send me a GPEC2a configured to my VIN, I have very little faith, but I'm trying every possible way, assuming they will not support my request I'll be more than grateful for your help and service!

[PurpleRam]

They can’t sell that to you because of emissions regulations, you can get them to go the other way, request. A Gpec5 with a 2020 model vin, for “better” emissions they will let you upgrade , but not down grade.

[N2speed]

Need to know what the communication protocol is. But as of right now Engine harness, Trans Harness and Body Harness. And that is if they all have the same connections to all the other plugs and sensors.

[castorjames]

Need to know what the communication protocol is. But as of right now Engine harness, Trans Harness and Body Harness. And that is if they all have the same connections to all the other plugs and sensors.

can you turn skym off and changue vin on a 2022-2023 trx pcm? currently working on a 2023 gladiator , installed a hellcat engine , any info on what other companies are doing for this swap? thanks

[castorjames]

hello any more info on this?

attached is a file from a 2020 jeep wrangler with demon swap.
it looks like it uses custom Operative system in both ECM and TCM??
any help in who can do this kind of work?

[N2speed]

hello any more info on this?

attached is a file from a 2020 jeep wrangler with demon swap.
it looks like it uses custom Operative system in both ECM and TCM??
any help in who can do this kind of work?

That is a Gpec2A PCM with a TRX calibration. it is still factory OS they just renamed the Calibration numbers.

[castorjames]

That is a Gpec2A PCM with a TRX calibration. it is still factory OS they just renamed the Calibration numbers.

thank you, i been trying to contact a2speed without any luck. i wanna send trx pcm to put jeep VIN and turn off SKYM.

how are they using that pcm in a gpec5 equipped vehicle?? they offer the hellcat/demon conversion for 20-21-22-23 years and all the conversion uses gpec2a pcm, also they uses 8HP75 transmission. in the file attached looks like they changued the OS name too but i dont know if they mod anything else in the tune.

currently i already installed the engine, removed the gpec5 and wired the GPEC2A, i can open and close switch, engine open throttle and everything, also fuel pump is commanded ... with the car off switch on if i turn the AC on i can see it communicates with PCM, because it shows AC on or OFF in VCM scanner, so communication should be same...?? i want to turn off skym on that pcm and put jeep VIN to try and see what i can do finish that car. currently it will not crank. maybe because antitheft?