What Can Cause the E2 Error on a Hopkins Reliance Trailer Brake Controller
Updated 05/01/2014 | Published 04/29/2014
Question:
I got an E2 code on my Reliance brake controller a mile down the road. Everything worked when I pulled out of the lot. Tough stopping a 7,000 lb trailer with a 6500lb truck! When I got home, had no eletric inside trailer. The battery ground wire had disconnected from the trailer. Question is: Could that have caused the E2 error code with the trailer brakes? Do the electric brakes have to be grounded? I havent moved the trailer yet and am getting the brake controller looked at tomorrow. Also, with the trailer disconnected, I get the proper E1 code while driving my truck
asked by: Ken P
Expert Reply:
The E2 error on your Hopkins brake controller indicates a short to the blue wire. The most likely culprit is a dirty or corroded vehicle/trailer connector and is causing power draw from another circuit to the brake circuit. Clean both connectors and also check the back where the wires attach because corrosion can build up there as well.
If this does not solve the issue, you should test the controller itself to see if it is the problem. Sever the blue wire a few inches from the back of the controller. Use a circuit tester like # PTW2993 if needed to test the end on the brake controller. Apply the manual override on full. The blue wire should show power. If it shows power at any other time then there is a problem with the internal circuitry of the controller, and it will need to be replaced.
If you are still getting the error the next most likely culprit is a malfunctioning brake magnet on the trailer. Start checking by inspecting the brake magnet wiring. Make sure the ground wires are attached to clean and corrosion free bare metal surfaces. Check the power wires to make sure they are not damaged and that there is no exposed wiring touching the metal trailer frame.
You can then visually inspect the magnets for wear. If you can see the windings coming through the magnets will need to be replaced. You can also check the magnets to make sure they are drawing the correct amount of current. I have included a link to an FAQ article that explains how to do this. I recommend using the section titled Testing Individual Brake Magnets.
The battery ground coming loose should not have caused this short unless the wire somehow made connect with the brake wire on the trailer and back fed to the controller but that does not seem likely.
