Lighting state detection for a vehicle trailer

A method of determining a connection state of lamps of a trailer, the method comprising:

• monitoring an on/off state of the lamps of the trailer;
• and
• when the lamps of the trailer are off;
• generating a first ramp signal for a first one of the lamps;
• monitoring a first response signal generated in response to the second ramp signal;
• and
• categorizing the connection state and a load profile of the lamps of the trailer based on the first and second response signals.

A trailer light controller comprising:

• a left lamp connectivity circuit electrically coupled to a connector to connect to a left lamp of a trailer, the left lamp connectivity circuit to produce a first test signal and condition a first response signal, the first response signal having a first timing characteristic based on a connection status and a load profile of the left lamp;
• a right lamp connectivity circuit electrically coupled to the connector to connect to a right lamp of a trailer, the right lamp connectivity circuit to produce a second test signal and condition a second response signal, the second response signal having a second timing characteristic based on a connection status and a load profile of the right lamp;
• a left lamp control circuit coupled to the connector to connect to the left lamp to control the on/off state of the left lamp;
• a right lamp control circuit coupled to the connector to connect to right lamp to control the on/off state of the right lamp;
• and
• processing circuitry configured to:
• categorize the connection state and the load profile of the left lamp based on the first timing characteristic of the first response signal, and
• categorize the connection state and the load profile of the right lamp based on the second timing characteristic of the second response signal.

A method of determining a connection state of a lamp of a trailer, the method comprising:

• monitoring an on/off state of the lamp of the trailer;
• and
• when the lamp of the trailer is off:
• generating a ramp signal for the lamp;
• monitoring a response signal generated in response to the ramp signal;
• categorizing the connection state and a load profile of the lamps of the trailer based on the response signal.