Troubleshooting the N.C. Error Code on the Tekonsha Prodigy Trailer Brake Controller

Updated 04/09/2011 | Published 04/08/2011

Question:

I have the Prodigy Brake Controller, P1/P2 and I connect the bargman plug into the rear of the truck. The brake controller will say connected C and then will go to not connected NC after a minute or so. It will then go back to connected after a minute or so also. Im not sure if it is the controllers problem or the trailer wiring problem. What could cause this?

asked by: Evan T

Expert Reply:

There are basically 3 possible causes leading to the brake controller to read that it is not connected to the trailer even if the trailer is connected. Since it shows the code with the trailer connected, it could be a short or open circuit on the brake output wire. There could be a missed connection or a bad ground causing the circuit to not be complete.

Though the problem could be on the trailer side, checking the wiring on the vehicle is also a good idea. Turn on the vehicle and have someone operate the brake controller. Touch one end of a circuit tester, like # PTW2993, to the ground pin on the 7-Way (7 o'clock position) and touch the other end to the brake controller pin (5 o'clock position). This should complete the circuit and the brake controller should read as though a trailer is connected. If it still reads the error code, you know the problem is on the truck side wiring and you will need to trace the wiring back to check for loose or broken connections.

On the trailer, the problem could be with the brake magnets. The magnet should have 2 wires; one should be grounded to the brake assembly or trailer frame and the other should be connected to the brake wire from the connector. Trace these wires back up to the trailer connector checking for frays, nicks, or bad connections. You may want to open the trailer connector and make sure this wire is still connected inside.

Finally, make sure that any dirt or corrosion in or on the vehicle and trailer side connectors is cleaned out. Corrosion build-up can cause a bad ground or short which would give you any number of errors on the brake controller. I have included a link to the installation details for the Prodigy for reference.

expert reply by: Michael H