The OEM trailer brake requires the "VIN must be updated with the sales code" as per installation instructions (
www.mopar.com/moparsvc/pim/media?id=9423704915998) . Step 19 shows two plugs being attached to the module. I'm assuming this is so the trailer brake shows up on the "screen" as per page 415 of the owner's manual:
4. Push the UP or DOWN button on the steering wheel
until “TRAILER TOW” appears on the screen.
5. Push the RIGHT arrow on the steering wheel to enter
“TRAILER TOW”.
6. Push the UP or DOWN buttons until the Trailer Brake
Type appears on the screen.
7. Push the RIGHT arrow and then push the UP or DOWN
buttons until the proper Trailer Brake Type appears on
the screen.
8. In a traffic-free environment, tow the trailer on a dry,
level surface at a speed of 20–25 mph (30–40 km/h) and
squeeze the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing
tires), reduce the GAIN setting; if the trailer wheels turn
freely, increase the GAIN setting.
Repeat steps 8 and 9 until the GAIN setting is at a point just
below trailer wheel lockup. If towing a heavier trailer,
trailer wheel lockup may not be attainable even with the
maximum GAIN setting of 10.
Am I correct in assuming that you have a functional trailer brake but you do not have the "VIN update" and functions as per 415 of owner's manual?