Troubleshooting Primus Brake Controller With PL Error Code When Installed on 2012 Mercedes Sprinter

Question:

Just in stalled your brake controller on a 2006 Sprinter Van and PL code is display all the time. Can tell us how to troubleshoot. Trailer is not hooked up and controller will not function at all.

asked by: Dale A

Expert Reply:

The PL error code means that there is a power interruption to the brake controller. The controller is getting enough power to illuminate the display, but not enough to correctly operate, which indicates there's something wrong on the circuit feeding power to the controller.

I'd recommend tracing the power feed from the brake controller to the battery. Ideally, you'll want the power to come directly from the positive battery terminal, this circuit should be protected by a 20 or 30 amp circuit breaker (9506P or 38630). Make sure all connections are tight and not corroded.

I'll link you to our FAQ article about troubleshooting brake controllers.

expert reply by: Mike L