Primus IQ Brake Controller Shows PL Code and Brake Pressure Numbers When Not Connected To Trailer

Question:

Hi The brake controller is on all all times. When it is not attached to my caravan it is showing PL. Now it has started showing bake pressure numbers. When I attach the caravan the brakes come on and make a humming noise. I am using a 12 pin flat to connect car to caravan. I would think and new controller is required. Your advice would be appreciated. Regards

asked by: Ian F

Expert Reply:

It sounds like there may be an issue with the vehicle wiring to the trailer connection. The Tekonsha Primus IQ # TK90160 having the lights come on when the trailer is not connected is suggesting that the braking circuit is some how being grounded to the chassis.

The PL is stating that there is some type of power interruption when the brake pedal is depressed. I recommend checking the connection at your 12 pin flat plug and tracing the wiring back to the brake controller to check for any damaged wires. You can also use a Multimeter # PT89ZR at the 12-way and along the wiring to check for continuity in the different circuits to see if the wires may be damaged inside the harness.

expert reply by: Bud M