This is what I found on it.
Snow Plow Lighting Enabled Mode New for 2019, when the snow plow lighting enable circuit (L312 Black/Violet) is powered with 12V+, signaling to the vehicle that snow plow is present, the ICON below will appear in the cluster. When the vehicle is in snow plow present mode the Adaptive Cruise Control, Front Park Assist and Front Collision Warning systems will be turned off. As in previous models when the snow plow present wire is enabled, the vehicle’s high and low beams will be disabled and the snow plow interface wires will be enabled. This means that the snow plow lights will now replicate all functionality of the vehicle’s headlights when requested (headlights, flash to pass, lock/remote start, etc.). The vehicle’s turn signals and park lights will remain active on the vehicle as well as becoming active on the plow. When high beams are requested on with the snow plow attached, the low beam output will remain on as well replicating the existing dual bulb headlight design on Ram trucks. This functionality is often called quad beam because it is intended for headlight designs that have 4 headlights total (2 low and 2 high). If dual filament bulbs are used on the plow (total of 2 bulbs used in the headlights), normally the low beam filaments should be shut off while the high beam headlights are on using an external relay or other type of switching device. Follow the snow plow manufacturer’s instructions. For trucks either sold in regions requiring Daytime Running Lamps (DRLs) or where the option was ordered or DRL lamps are turned on. The snow plow DRL function uses the turn signal output drivers. * Provisions must be made by the plow manufacturer or installer to insure the plow lighting meets governmental requirements.
