Commander 4WD V8-4.7L VIN N (2006)
Trailer Lamps: Description and Operation
TRAILER TOW WIRING
In addition to the trailer tow wiring provisions, vehicles equipped with an optional trailer tow package include right and left trailer tow stop/turn relays
installed in the IPM. When the FCM receives the appropriate inputs for normal turn signal, hazard warning or brake lamp operation, it responds by also
energizing or de-energizing these trailer tow relays. When a trailer tow relay is energized, it provides battery voltage from a fused B(+) fuse to the trailer
lamps through the trailer tow wiring to synchronize the illumination and flash rate of the trailer brake and turn signal lamps with those of the tow vehicle.
In certain export markets, instead of trailer tow relays vehicles equipped with a factory-installed trailer towing package have a Trailer Tow Module
(TTM). The TTM provides the appropriate outputs to the trailer electrical system through the trailer tow connector based upon both hard wired inputs
from the vehicle electrical system and messages received from the FCM over the CAN data bus. The TTM also monitors the condition of the trailer
lighting through circuit resistance and provides both visual and audible feedback to the vehicle operator by sending messages back to the FCM which
increase turn signal flash and click rates when a problem is detected. The TTM messages the FCM when the trailer wiring is connected, then the FCM
suppresses operation of the rear fog lamps on the vehicle while the TTM implements operation of the rear fog lamps on the trailer.
