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!