Trailer Turn Signal Lamp Operation
WARNING: This page is about a different car, the 2011 Suzuki Equator. However, it is still accessible from the selected car via links, so may be relevant.
The trailer turn signal lamps are controlled by the BCM. When the combination switch (lighting and turn signal switch) is in the LH or RH position with the ignition switch ON, the combination switch (lighting and turn signal switch) sends a signal to the BCM. The BCM detects the TURN RH or TURN LH ON request. The BCM sends a control signal to the respective trailer turn relay which sends power to the trailer connector.