Troubleshooting Factory Brake Controller Not Working and Trailer Disconnected Message on 2015 F-250

Question:

2015 Ford F-250 The trailer discounted comes up The trailer brakes won’t work. If I try to press any Button on the factory controller the message appears again. All the lights work only the trailer brakes don’t. I checked all the fuses I’ve replaced the module and the connector at the rear

asked by: Cesar

Expert Reply:

Typically when you start seeing the "Trailer Disconnected" error on trucks like your 2015 Ford F-250 that are equipped with the factory brake controller, the issue is coming from somewhere along the brake output wire between the controller and 7-Way. Since you replaced the 7-Way and module at the rear, you know the problem isn't there. All the fuses are okay as well which means the controller should be getting appropriate power for operation.

At this point I recommend testing the brake output pin on the 7-Way connector (5 o'clock position) with a circuit tester like # PTW2993 while you have the manual override on the brake controller applied. This is just to quickly try and rule out a potential issue on the trailer side.

If you don't get power then you at least know the problem is somewhere on the truck. If you do get power though, then the problem is actually on the trailer. If this is the case you will want to inspect the trailer side 7-Way for debris/corrosion in and around the pins, cleaning out as needed, and make sure all the grounds are securely attached. This includes the individual ground wires from each trailer brake assembly.

Otherwise if you didn't get power it's really just going to be a matter of trying to inspect and test the brake output wire that runs to the 7-Way from the factory brake controller. This is likely going to be pretty difficult so your best route to repair the controller will really be to bring it up to a local Ford dealer.

If you'd rather not do this then another option would just be to replace the factory controller with an aftermarket unit. For this I strongly recommend looking at the Curt Echo # C51180. This wireless unit just gets plugged into the 7-Way on the truck and pairs to your smart phone via Bluetooth. You use your phone to adjust any settings or activate the manual override so you don't have to mount an additional component in the cab like with most other options. It will also completely bypass the factory controller so you don't even have to mess with it at all.

I have attached a short video demonstration below that you can also check out.