Trailer Battery Charging

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

The TRM provides voltage to the trailer tow connector for trailer battery charging when all the following are true:

the TRM detects that a trailer is connected
the ignition is on and engine is running
a brake pedal application has been detected in the present ignition cycle
the BCM load shed strategy is not active (a message will be displayed in the instrument cluster, such as "Low Battery Features Temporarily Turned Off" or "Turn Power Off To Save Battery", to indicate that BCM load shed strategy is active)

The TRM directly (no relay) supplies fuse protected voltage for trailer battery charging. The TRM is supplied voltage for trailer battery charging from the BJB.