Stopping Trailer from Jerking When Brakes are Applied with Proportional Brake Controller

Published 07/22/2016

Question:

Finally got controller adjusted to stop smooth on smooth road but when brakes were applied going down long 6 grade it jerked violently. Is the power set too high ? It is set on 6. Pickup weighs 8200 pounds. 5th wheel weighs 17000 pounds. The boost is set on 3.

asked by: Athen L

Expert Reply:

It does sound like the Prodigy P2 # 90885 controller was set too high and caused you to experience brake reverberation. This happens when the brakes are set too high and cause the trailer to jerk when they are applied. When the trailer jerks, the brake controller senses it and thinks the vehicle is decelerating even more, so the controller applies the trailer brakes more strongly. When the brake is applied even stronger, the trailer jerks again and the situation continues to spiral. This is certainly a very scary situation to find yourself in.

I spoke with my technical contact at Tekonsha and he suggested beginning to readjust the controller with the boost setting. You mentioned that the boost is set at 3, so he strongly suggested setting it at 2, based on the jerking you experienced and the weight of the trailer. This should help the brakes not be applied so strongly and prevent the brake reverberation.

If even after you lower the boost setting you still notice this jerking, my contact then suggested lowering the power/gain setting by one level, from 6 down to 5. It is best to adjust this power in small increments so that you do not short yourself on breaking power.

expert reply by: Victoria B