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Thread: 3800 SC Pcm/Harness running Chrysler

  1. #1
    Advanced Tuner
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    Apr 2015
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    3800 SC Pcm/Harness running Chrysler

    I have a family member that is looking to modify his (1998?) 2.5 v6 Chrysler Sebring.

    He wants to turbo the motor and possibly swap the 3.0 block into it etc etc.

    There is not a tuning interface on the planet that i have found that can modify the factory PCM in those cars.

    We have been looking at megasquirt also, but then I got the idea for using a GM harness.

    Since we can use or replace any sensors needed on the motor to make the computer "think" its a GM 3.8 I think it will work. This os is already 2 bar, and I am quite familiar with HPT so it feels like a better fit since an engine harness rewire is already required.

    My question is really, what does the 3.8 PCM need to see that the motor wont have? I know crank trigger (i just dont know exacly which one, but an external trigger is easy enough). Does this OS require a cam signal too? I'll be using the ICM and all the engine management from the 3.8 if I can.

    Has anyone else done anything like this in any other vehicles?

    The Chassis side of the equation im not super worried about. we can either free-wire all the electronics inside and use aftermarket gauges, or we can piggyback the chrysler pcm and see if that works too.

    As long as I can get the motor to fire and run on the 3.8 PCM, the rest should be relatively easy.

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
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    Rogers, MN
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    It needs a crank and cam sensor/signal. Factory has a sensor behind the crank pulley/balancer for crank signal.

    It does run a 2 bar map to read up to 14.7 psi but the pcm is MAF based for basically everything. Factory VE table stops at 105 KPA and really isnt a huge factor, I've never tuned the VE part of a 3800 computer. It relies on the MAF to make fueling and timing decisions.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.