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Out with the NEW... In With the OLD CP3

1115 Views 2 Replies 2 Participants Last post by  Captainmal
Had my CP4 injector pump replaced with the old CP3 design. Never saw a designation of CP3.3 but it just may be that. Couple things of interest. One is there was a programming change to the PCM, not the ECM. I do not know the nature of the change and neither did the service advisor. Second was a change in the power steering line that I had never heard about. The first picture below is the new faulty design CP4 that was removed.
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Here is the new/old CP3 they just put in. You sure can see the differences.
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There is a module kit used and this paperwork details that and more.

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So now there begs the question of how does it work?

Only have the 35 mile ride back from the dealer to offer an opinion. Never noticed any change in operation. The drive back started in downtown Bradenton, Florida in hideous traffic and lights. Then I got on the Interstate for about 12 miles and finished the ride with about 12 more miles of rural road back to the house. I re-set this EVIC mpg readout right after I cleared the first stop light after leaving. That's when I thought of it. There were many more so did not miss much. Took this picture after I pulled into the driveway at home.
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Pretty typical readout for my mpg without towing. Now that will NOT be correct as my EVIC is most always a full MPG higher than calculated mileage. Sometimes it can even be a little more than 1 mpg too high. My guess is it should actually be in the low to mid 21's based on the BS I had to initially drive through. My conclusion after such a brief test distance is, "little to no change" in fuel mileage.

CP3 or CP4 ... the difference is design and reliability. I am happy to get the old reliable. Thank You Stellantis.
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Read that the reason so many 2019's were rejected from getting the CP3 is programming. Seems some of the earlier recalls for things like ABS and windshield wipers changed the PCM programming. Then that programming was not set up for the change to the CP3. That caused some issues and is the reason for the delay to change so many 2019's. I never had any of the earlier recalls done so Stellantis approved and did my change and all the recalls with one flash sequence.

Is that correct? No clue. Just one thing I have heard. There are many who are continually getting rejected from the CP3 change. Like the Ecodiesel, if the CP4 goes there is hell to pay. I and all the informed owners of 2019-2020 Cummins trucks do not want that kind of breakdown. Covered by Stellantis or not, the breakdown is seriously difficult for owners. Glad I got it done. Kind of like the Gen 2 Ecodiesel owners wishing they could get a Gen 3 engine one. It takes big money to buy a 2021 or 2022 Cummins. Same can be said fo buying a 2020 or newer Ecodiesel when you already have an older one.
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