P2 Trailer Brake Controller Tries to Apply Trailer Brakes without a Trailer Connected

Question:

hi my controller is applying the brakes but their no trailer hooked up

asked by: Chad

Expert Reply:

Since there is no trailer connected the P2 should show the 2 dots even during a braking event. Since yours is showing the power output with no trailer connected it could be a short or some sort of minimal power draw that makes the controller think there is a trailer connected. The most likely cause of this is dirt and corrosion on the pins of the trailer connector on the vehicle and/or around back where the wires attach to the connector. If you give it a good cleaning that may solve the problem.

If it does not, make sure that the controller is mounted according to the instructions. it cannot be tilted or turned to one side or the other. If it is, that can cause erratic behavior. After making sure it is properly mounted, if the problem persists then reset the controller by unplugging it for a few minutes. Then plug it back in and run through the set up process as indicated in the instructions, linked for reference.

To determine if there is a problem with the controller you will need to sever the blue wire a few inches from the back of the controller. Then use a circuit tester, like # PTW2979 if needed, to test the end of the blue wire coming out of the brake controller. It should only show power when you apply the manual override. If it shows power at any other time then the controller is bad and will need to be replaced.

expert reply by: Michael H