Troubleshooting Prodigy P2 Trailer Brake Controller That Only Functions at Maximum Output

Question:

My brake control module will not adjust. The boost/gain stays on full all the time. Any idea whats wrong?

asked by: Robert K

Helpful Expert Reply:

Thank you for your many purchases from etrailer, including that for the Tekonsha Prodigy P2 trailer brake controller # 90885 which is among the most popular options that we offer.

The issue with the unit operating only at maximum power and maximum boost no matter where you have these two controls set suggests, according to my technical contact there, either an open ground between the trailer and vehicle, or a short between the brake circuit contact and the adjacent one for the right turn/stop circuit.

You can check this by carefully inspecting the 7-way for signs of corrosion, which often occurs INSIDE the socket or inside the vehicle plug that connects to the back of the socket. Disconnect everything you can and inspect/clean as needed to remove any corrosive build-up. Do the same with the trailer's 7-way plug. You can refer to the link article on wiring to see the pin/function assignment on 7-way setups.

Please note that the P2 display does not indicate the power setting you selected but rather the actual voltage output from the controller, which travels on the blue output wire back to your 7-way.

expert reply by: Adam R