Troubleshooting Tekonsha Primus IQ Brake Controller # TK90160 Error Codes

Question:

got the code OL displayed and the chart on your site says its an overload condtion. What does overload refer to. electrical current over load or do I not have the boost high enough. I also go an SH at the same time so would a short cause the overload display? Does this mean the unit needs to be replaced. What do you recommend.

asked by: Gene L

Expert Reply:

Typically getting the OL and SH codes could have a few different meanings. There could be a short on the brake output wire (blue wire) somewhere between the brake controller and trailer brakes. If you only have this issue when the trailer is connected, then there is a good chance the problem is on your trailer. Another potential cause for this could be moisture in the trailer connector.

I would start by checking both the trailer and the vehicle connectors to make sure there are no signs of corrosion or dirt trapped. Clean or replace as needed.

Also check the trailer's entire brake circuit wire from the trailer connector all the way along the wiring (looking for signs of cracked or worn insulation) back to each brake assembly. If the brake circuit wire has any damage this could cause a short that would lead to the overload and short circuit error messages. Repair or replace any damaged wire.

If no wiring problems are found you can test the brake magnets themselves by following the procedure outlined in the linked article. You will need a multimeter similar to # PT89ZR. If you do find your magnets are worn we offer replacements that can be viewed on the included link.

expert reply by: Erik B