No Trailer Connected Error for Prodigy P3 on 2009 GMC Sierra with OEM Brake Controller

Question:

Installed new p-3 in truck very simple. Wired correctly, but when plugged in trailer pigtail controller says trailer is not connected , and dash board says service trailer brake system. Unhooked power wire to p-3 and reinstalled power wire to factory controller and system works .

asked by: Mike M

Expert Reply:

Thank you for all of the details! Since your 2009 GMC Sierra has the factory integrated brake controller you need to run your own 10 Gauge Wire # 10-1-1 from the blue wire on the Prodigy P3 # 90195 back to the brake output pin on your truck 7-Way socket. This is because you have to essentially bypass the wiring for the OEM controller. I recommend using heat shrink butt connectors # DW05745-5 to make your connections.

We actually have a helpful article written about this procedure that I'm linking for you to check out.

expert reply by: Jon G