Will Out of Adjustment Trailer Brakes Cause a Fault Code on the Electric Trailer Brake Controller

Question:

I have al-ko 12-2 trailer brakes and need to know if they are out of adjustment could that cause a trailer fault code?

asked by: Patrick

Expert Reply:

The brake pads themselves being out of adjustment would not cause a fault code to read on your brake controller. You can check the brake pad adjustment by safely raising the trailer and spinning the tire. If you hear a slight lining drag as the tire spins, and can easily spin the tire your brakes are properly adjusted. If the tire is hard to spin or you hear intermittent or no lining drag the brakes should be adjusted. We have a video that shows how to adjust the trailer brakes at the 4 minute 35 second mark, see link.

Most likely the fault code is due to a wiring issue or brake magnet wear. The first thing I would check is the trailer connectors on the vehicle and trailer. Make sure there is no corrosion inside or out that is causing the brake output wire to short to ground or another circuit, and make sure the wiring is connected properly, see wiring diagram link.

Next, check the brake magnet wiring on the trailer and make sure all of the grounds are connected to clean metal and the connection points are good with no cuts frays or shorts of any kind in the wiring.

Finally, if the above wiring checks out, you will need to remove the hub and check the brake magnet itself for wear and proper function. If you can see windings through the magnet surface or if there is abnormal wear on the magnet, the magnet will need to be replaced, # BP01-180.

If you do not see wear you can check to see if the magnet is shorted by touching the base of the brake magnet to the negative post of a 12 volt battery. Then, connect one of the brake magnet wires to the negative lead of a multimeter, and the positive lead of the multimeter to the positive post of the battery. If any amperage is detected the magnet is shorted and will need to be replaced. I have linked a trailer brake magnet testing article for you to review.

expert reply by: Robert G