What Does the SC Error Code Mean on the Activator II Trailer Brake Controller

Expert Reply:

On the 2-8 Electric Brake Controller, item # 5500, the code SC indicates that the brake controller output circuit is short circuited at some point between the point where the blue wire exits the rear of the controller and where it ultimately ends at each brake assembly at the brake magnet.

The most common situation that causes this is a damaged or corroded trailer connector, either the socket on the vehicle or the plug on the trailer. Carefully examine the metal pins on the plug and socket for white or green corrosion. If any is visible, it is possible that the corrosion might have spread to the interior of the connector where the wire actually attaches to the terminal on the connector itself. The corrosion can prevent the voltage from passing through the connection or cause the circuit to come into contact with an adjacent terminal, causing a short.

After examining the plug on the trailer and the socket on the vehicle, trace the blue wire that carries the brake voltage from the trailer connector to the brake magnets. Make sure there are no loose connections, or pinched or broken wires. Look for wire insulation that is worn or cracked. If the copper wire has been exposed and allowed to contact the trailer frame, a short is likely.

Make sure the brake magnets are wired correctly. Each brake magnet will have two wires leading from it. One should attach to the brake wire you traced back from the connector, the other should be grounded to clean metal on the trailer frame.

expert reply by: Andi