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Thread: Using 2019 L86 ECU on 2017 L83 engine?

  1. #1
    Potential Tuner
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    May 2020
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    Using 2019 L86 ECU on 2017 L83 engine?

    Hi there,

    I recently purchased a used L83 and T56 to swap into my 280z that was supposed to come with the original ECU. However, after looking at it I noticed it is out of a 2019 6.2 from a cadillac escalade. I went ahead and tried to make it work but I'm having trouble getting things to a driveable state.

    I started out by copying most of the tables from a stock L83 tune over except for a few airflow relates ones which I copied from a 2016 camaro as I am using the camaro intake and throttle body. I've since modified a few different tables to try to get things working, but I haven't had much success yet.

    From idling the engine and one short drive it seems like the engine hangs at around 1500 rpm on accel and decel and is very slow to decrease in rpms in general. Sometimes the engine will continue to climb in rpms until I shut the car off. The car also seems to buck if I let off the throttle at all.

    I hadn't intended to really tune the car any, I'd rather the engine just ran in stock form with a manual transmission and the intake manifold swapped.

    I've attached my tune file. Am I going to run into issues trying to make modifications to the 2019 ecu on the 2017 5.3 engine? Or am I missing something else. I feel like I'm missing something important.

    Any help appreciated, thanks.
    Attached Files Attached Files

  2. #2
    Potential Tuner
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    It looks like I would need to do a segment swap to use the T56 which may be where some of my problems are from.

    Does anyone know of how to find or have a manual tune for OS: 12698119?

  3. #3
    Advanced Tuner
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    Aug 2016
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    All 2019 L86 calibrations were for automatic transmission applications and as such they expect there to be a TCM present which reports information such as vehicle speed output, the position the gear selector is in, etc. You don't have any of this.

    A "segment swap" won't be enough to solve this as the parameters that need to be swapped transcend all of the segments in the ECM.

    Your best bet would be to flash in a 2017 Camaro LT1 / manual transmission OE flash, then copy over your L83 specific parameters. You may still have challenges without a clutch pedal position sensor present, and also you will probably still need to get the vehicle speed sensor wired up to your ECM.

    Good luck

  4. #4
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    Thanks for the response, that was my suspicion from what I've been reading. Didn't want to spend the 4 more credits until I had some confirmation. I'll give that a shot.

    I wired up the VSS a few days ago, didn't seem to work, but like you said the ecu was probably looking for speed from the TCM rather than the vss pin.

  5. #5
    Tuner in Training
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    Do you happen to have the manifold volume for the L86 intake? I just did a swap and I need those numbers to get a proper tune

  6. #6
    Advanced Tuner IARLLC's Avatar
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    915.97 cu/in

    Yep. Whenever I have installed a manual in an auto rig I have always had rpm hang until programming the pcm to a stock manual program. Then I tune it.

  7. #7
    Tuner in Training
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    Did you ever get it running solid? Curious what you did.