Tekonsha # TK90160 Brake Controller NC or OC Error Message on 2018 Nissan Pathfinder

Question:

Hi there I keep getting an OC or NC signal. my trailer lights and signals all work i am going to try to get clean the connections hoping that will work. any other thoughts?

asked by: Suzanne

Expert Reply:

If you find significant corrosion you may need to replace the connector with # HM40975 for the vehicle wiring or # H20042 for the trailer end. However, if cleaning the 7 way connector on your 2018 Nissan Pathfinder doesn't correct the errors then it's likely that you have a short on the electric brake circuit or there is a problem with the brake magnets themselves.

What we first want to do is isolate either the vehicle or the trailer as the source of the problem. Using a circuit tester like # PTW2993 to test the brake output circuit at the vehicle's 7-way connector using the manual override lever. If your vehicle 7-way connector has a brake signal on the brake circuit pin (pin at 5 o'clock -see attached diagram) and you do not get an error code, then we've isolated the problem to the trailer wiring.

If you don't have a signal when checking the 7 way on the vehicle or continue to see the error code, go to the brake controller and cut the blue wire about 6" back from the brake controller. Use the tester while pressing the manual override to test the blue wire coming from the controller. If there is an output signal there with no error code then there is an issue in the vehicle wiring between the brake control and 7 way connection. Trace back the blue wire between the controller and 7 way connection to check for damage- this could be causing a short. You could also just run a new wire from the brake controller to the 7-way to bypass the factory wire completely using part # 10-1-1 . If you don't have power behind the controller it means the controller has gone bad.

If the truck side checks out fine, then the issue is on the trailer. Trace the brake circuit wire from the trailer connector all the way back to the brake assemblies. Look for cracks/cuts or worn spots in the insulation. Make sure the wires aren't rubbing against any sharp corners or edges of the trailer and also make sure that the wiring is clear from any suspension components. Make sure that the ground wire is tightly secured to a paint and debris free spot on the trailer frame; repair or replace any damaged wires as needed. Finally, check the wiring at each of the trailer brake assemblies. Each brake magnet must be solidly grounded to a paint and debris free metal surface. Make sure both wires are firmly connected to each brake; also inspect the magnets themselves. If you can see the copper winding then the magnets are bad.

If these steps still don't address the problem, get back to me and I will continue to keep troubleshooting with you.