Primus Brake Controller ER Error Code Troubleshooting

Updated 03/27/2019 | Published 03/26/2019

Question:

My older Primus brake controller is displaying error code 7 trailer not connected, but I cant find any information as to what this means. If there is a wiring fault somewhere, Id appreciate any guidance you might be able to give as to where to look. It is an older unit, so it may just be worn out. Thanks

asked by: Kent D

Expert Reply:

The ER would mean there is an internal error on the inside of the brake controller that cannot be fixed. I believe that is the code you are experiencing. The brake controller will have to be replaced. The P2 # 90885 will use the same plug as the Primus so it is a great option for a replacement. It uses the latest generation of inertia sensor and is much more reliable.

expert reply by: Jameson C