Troubleshooting N.C. Display on Tekonsha Prodigy P2 Brake Controller

Updated 08/19/2014 | Published 08/16/2014

Products Featured in This Question

Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional

(2763)

$159.00

Hook Probe Circuit Tester

(60)

$12.27

Question:

Hi, i purchased a Prodigy P2 brake controller from you all a couple weeks ago and used it with my popup trailer on a trip from colorado to Minnesota last week. Everything was great on the way out - no issues. On the way back, however, the controller started to say n.c. which means it doesnt sense a trailer connected. However, the trailer was connected and lights and such were functioning. In fact, when i operated the manual brake lever on the controller it worked and i could feel the trailer braking even though the controller continued to say it wasnt connected. about half the time when operating the manual lever, the controller would then display the trailer as connected for a few minutes before going back to no connection. The wiring harnesses are tight and fully connected. The rest of the system is the factory installed wiring and towing package on my 2012 GMC acadia. The trailer is a coleman pop-up. Brakes were checked and verified by a local RV mechanic before the trip. Please advise how to troubleshoot this.

asked by: Christian E

Expert Reply:

There are 4 potential problems that are stated in the instructions (linked at right) that could cause the NC (no connection) reading on your Prodigy P2, # 90885. I have also included a couple of links to wiring and brake controller information. The 4 possible causes for NC are as follows.

1. Trailer not connected to tow vehicle.
2. Trailer connected with open circuit on brake line.
3. Trailer connector disconnected or corroded.
4. Loss of trailer brake magnet ground.

Testing the Prodigy P2 brake controller is fairly easy. Sever the blue brake output wire and then apply the manual slide. Using a circuit tester like part # PTW2993, you should get output to the trailer brakes. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is farther back either in the vehicle wiring or on the trailer.

If either the brake pedal or the manual slide is not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.

If there is power on the red wire before the brake pedal is pressed, you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.

If these connections check out and the brake controller is properly grounded, then there is possibly a problem inside the brake controller. Unfortunately brake controllers do not have any internally serviceable parts, so the brake controller would need to be replaced.