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Thread: ZF8HP70/75 TCM updating for Autostick

  1. #1
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    Oct 2022
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    ZF8HP70/75 TCM updating for Autostick

    I'm trying to find a way to update from a rotary (4 POS PRND) to a polystable shifter in my Durango. The 14-17's had the rotary knob, while the 2018+ cars had a polystable T-shifter.

    The mechanics of the shifter all swap over, and the wiring pinouts are all the same. The shifter type is changed to the "5POS Polystable eshifter", and everything works EXCEPT the +/- function of the T-handle itself while in M-mode. The paddle shifters still work and function correctly, but the +/- on the T-handle don't.

    Is there a TCM setting that needs to be changed to enable what inputs allow "manual" shifting?

    Combing through wiring diagrams side-by-side, here is what I found:

    • The audio switches in the steering wheel (which include the paddles) are LIN BUS slaves. When you flick the paddle, the LIN signal goes to the SCCM (Steering Column Control Module), which then outputs to the CAN-C bus. This tracks for both 14-17 and 18+ cars.
    • The function for the T830 circuit is "Paddle Shift Switch Signal" on both MY ranges. It ends at the SCCM. The SCCM does not
    • The Shift-by-wire module/ESM connector has "DATA BUS(+/-) ESHIFT" and CAN C (+/-). This, again, is true for both MY ranges.
    • The TCM also has "DATA BUS(+/-) ESHIFT" and CAN C (+/-) for both MY ranges.
    • The above 4 I/O's are the only real data besides the Park signal and the Ign signal.
    • The ESHIFT signals ALSO go to the headlight control module in both ranges. I imagine this is because light behavior is tied to gear (PRND). The connector pinouts change between the ranges, but the ESHIFT wiring is in the same pins
    • The circuit identifier for the CAN +/- out of the ESM and into the TCM is D429 and D430 for both MY ranges. Same goes for the ESHIFT identifiers (D440 and D441).


    From what I can tell, the ESHIFT signal is on the D-PT Bus and goes from ESM to TCM directly. The ESM communicates with the BCM via CAN-C. The paddle's do NOT have an ESHIFT signal, and they communicate only with the BCM via the CAN-C bus (through the SCCM). All of that is to say, I think the paddles and the ESM follow completely separate pathways to the TCM. That is UNLESS the autostick functionality of the ESM is handled entirely by the BCM. In that case, a +/- move on the T-handle sends a message on CAN-C and NOT on the D-PT/ESHIFT bus.

    If the +/- signal is only on the CAN-C bus to the BCM, then why won't the BCM enable the +/- functionality at the T-handle? Swapping the shifter type on the BCM gets the T-handle to not throw a Service Shifter code in M-mode, but the +/- still don't work.

    If the +/- functions are on the D-PT/ESHIFT bus, then it would be logical that the TCM can't interpret those signals because the TCM is for the 4POS Rotary shifter. If this is the case, then there MUST be a setting in the TCM that will enable the +/- functionality.

    Does anyone have any insight, or even a log of the entire TCM from a 2018+ Durango and a 2014-2017 Durango so I can compare?

    Thanks!

  2. #2
    This would be a great feature to add, I hope this gets more attention

  3. #3
    Tuner
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    Aug 2018
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    SK, Canada
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    Have you updated the BCM with something like AlfaOBD to change the shifter type?

  4. #4
    Tuner in Training
    Join Date
    Dec 2019
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    think you need a tcm swap. dont think you can reflash a different os on them. are there any actual vehicles that have BOTH a manual mode +/- shifter AND paddles? if so, thats probably the vehicle to grab a bcm copy from to check its config, and probably tcm as well.
    are you getting actual manual mode behavior at this point, or just ERS function?

  5. #5
    Quote Originally Posted by mike_ct View Post
    think you need a tcm swap. dont think you can reflash a different os on them. are there any actual vehicles that have BOTH a manual mode +/- shifter AND paddles? if so, thats probably the vehicle to grab a bcm copy from to check its config, and probably tcm as well.
    are you getting actual manual mode behavior at this point, or just ERS function?
    My Ram Eco has AutoStick type shifting enabled, but was not tuned with HPT. Ive ran 2 different Trans tunes and was able to save both files on HPT, and HPT shows different OS between the 2 different tunes, but did not need to do a TCM swap. I shift it with the steering wheel + - buttons, and love it. Absolutely changes the whole character of the truck... only thing I see that it does is use Shift ID 27 once I Enable it by pressing + or - on the wheel.

    However I never took a read file of my Stock Trans tune to compare my original OS to the tuned files.

    It would be cool if we had the same ability like the GM's have with TUTD drop down menu, and we could configure it how we like.
    Last edited by Smxtmpr34; 1 Week Ago at 06:29 PM.

  6. #6
    Tuner in Training
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    Dec 2019
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    what product did you use to reflash different TCM OS? HAven't been able to do that with HPT or get autostick type working on my ram. Would love to be able to do this without swapping the TCM.

  7. #7
    Tuner in Training
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    Apr 2022
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    you need Alfa OBD. its 50$ for the program plus you need a obd dongle. the hpt dongle wont work

    go to your vehicle, body control module, scroll all the way down to "configure body control module" and then shifter type.

    now with that said you need the tcm to match the shifter... you cant just switch the shifter its self. if you get a shifter from a donor car you need the tcm for the same corresponding years.
    example would be the 2014\15 jeeps have the T handle shifter, in order to switch to the 2016+ shifter like youre talking about i would need the tcm from that year too.

    hope this helps