Troubleshooting the SH Error Code on a Tekonsha P2 Trailer Brake Controller

Question:

What is code s.h.

asked by: Stan A

Expert Reply:

The SH code on the Tekonsha P2, # 90885, indicates there is a short circuit that the controller is sensing on the brake output (blue) wire. There are a couple of common causes.

The first thing you will want to do is sever the blue wire from behind the controller a few inches. Leave enough wire so you can reconnect it later. Then use a circuit tester like # PTW2993 on the side coming out of the controller. It should show power only when you apply the manual override. If it does not or it shows power at any other time, then there is a problem in the controller, and it will need to be replaced.

If the controller checks out, then reconnect the blue wire. Next you can check the trailer and vehicle side connectors. A dirty or corroded trailer connector can cause a short. Clean out any dirt or corrosion you find. Corrosion can also build up in the backs of the connectors where the wires attach.

Next check the trailer wiring to the brake magnets. You will be looking for any nicks in the wiring that show exposed wire touching the trailer frame. Also check the trailer magnet ground wires and make sure they are attached to clean and corrosion free bare metal surfaces.

Then you can inspect the magnets. If you can see the windings coming through they will need to be replaced. To further test the magnets, I have included a link to an FAQ article that will help you.

expert reply by: Michael H