Jake/CECU Wiring

I have a 2014 pete 337 with px9 (isl8.9) and cm2350 ECM, which currently has a VGT engine brake. I bought all the hardware to add jakes, however I can't figure out the wiring, and the pete store wont show me schematics or give me any help.

The cummins wiring diagram shows me pins 7 & 9 on the 2350 ecm engine harness are the output voltage for the front and rear solenoids, but it doesnt show any jake signal pins on the OEM side like the older 2250 ecm has. I'm guessing the jake switches on my truck need to be wired to the CECU which will communicate with the ecm via multiplex, but I pulled the dash apart and couldn't find any prewired harness breakouts to add the hi/lo switch.

Is my VGT on/off switch functional in its current wiring for the jakes after the computer gets flashed to enable the jakes? Where does the hi/lo switch get wired to on the CECU?