PL Code Troubleshooting on a Prodigy P2 Brake Controller

Question:

Right now im thinking its a ground issue because i am getting no signal out of the blue wire when i check it with my circuit tester... But however when i do the circuit tester it must be getting ground because all of the sudden i get connection ... But which ground? The one to the module or the one at the 7plug in the rear? Im leaning towards the ground that i have to the battery but i had to take a break so i thought id see what yall say. Thanks!

asked by: Tyler

Expert Reply:

A brake controller will sense a trailer connected to it when a load is put on the circuit. A circuit tester will put a slight load on the circuit and can fool the controller into thinking that it is connected to a trailer. That would explain why your controller is saying it is connected when a tester is applied to the circuit.

The PL code will be displayed when the Prodigy loses voltage on the black wire while either the brake pedal or the manual lever is being applied. This may be caused by a loose connection or I have also seen a faulty circuit breaker cause this as well. Check the connection of the black wire to your vehicle as the problem most likely lies there.

I attached a help article on troubleshooting brake controllers as well.

expert reply by: Jameson C