What Do the SH and OL Error Codes on Tekonsha Prodigy 2 Brake Controller # 90885 Mean

Question:

I get an intermittent SH error code while towing my camper and the OL code when I apply the brakes. I just transferred my Prodigy brake controller from my GMC truck to my new tow vehicle 2020 Nissan Pathfinder and have now got these alarms on my first 2 camping trips. I have never had these codes while pulling with my GMC and the same camper. Wiring on the Pathfinder is factory installed. I have been trying to check for a grounding problem but, since it is intermittent, I have not been successful. Should I continue to concentrate on the camper wiring 7 way plug, etc or is the Prodigy itself or Pathfinder a possibility?

asked by: Andrew L

Expert Reply:

On your Tekonsha Prodigy P2 Trailer Brake Controller # 90885, the SH code indicates the controller "sees" a short during operation. The OL codes indicates that the controller is drawing too much current. These codes do indicate a wiring issue of some sort, but first let's try to reset the controller to see if that corrects the issue.

The first thing you can do is reset the the brake controller. You can follow these steps to reset the controller:
- disconnect the trailer from your vehicle
- disconnect the brake controller by unplugging the harness from the rear of the unit
- plug it back in
- the display will show NC for 15 seconds and then should have 2 dots.

If that doesn't fix the issues you can troubleshoot them each separately.

The SH code could be caused by a short on the output circuit. A possible cause for this is dirt or corrosion buildup on the trailer or vehicle. There are 4 methods to troubleshoot the brake controller:

Method 1 - Verifying correct wiring on the hard-wire installs and plug-in installs
Method 2 - Testing for the brake signal
Method 3 - Looking for a short or ground issue
Method 4 - Inspecting the brake assemblies

I am attaching a link for troubleshooting the brake controller that explains each method more thoroughly, as well as an article on how to check the brake magnets.

The OL is usually the result of either a short on the brake output wire on the trailer or low resistance to ground on the brake wire. You can check for pinch points, worn or cracked insulation that would cause the output wire to short out. You should also check the ground leads from each brake assembly to ensure they are not corroded and are grounded to bare metal.