OEM trailer brake controller problem, "trailer not connected"
 

Hi all. I need a hand please. My truck is an '11 FX4 with the tow package. I've installed the OEM integrated trailer brake controller. I took it to the dealer yesterday to have it activated. The problem is that when I hook up my trailer the display on the truck reads "trailer not connected". All of the lights work properly, I've checked the grounds and when checked the connection for the brakes where the trailer plug is spliced into the wiring harness.

The bizarre part is that if I move the manual slider on the TBC it will engage the brakes (but still shows not connected). I used a test light on the truck side of the plug to check for voltage. I am getting power to the brake wire with the slider but not if I depress the brake pedal.

Any advice?

You did install the fuse and relay with the controller? If so I think there is a tsb on the controller.

I remember something like this a year ago when I got my trailer, and I'm drawing a blank....

Yes, that’s bizarre. Have you used this trailer before on another vehicle or controller? Does Gain do anything?

I did install the fuse and the relay in the panel.

@f6bits- If I press the gain + and - buttons the changes are displayed on the in-dash LCD panel as the change is registered but under that it says "no trailer".

I knowthe prblem you are having. Are you using an adapter for your trailer? My truck does exact same thing if I use an adapter that does not have a center pin. My trailers are older and have the old style round 6 pin connector.

No adapter.

I had the same problem, it was showing "trailer disconnected " on my truck and brother in laws truck, ended up being a bad plug on trailer. Changed plug and it works fine.

Yep, check plug on trailer. Mine had some tarnished contacts. Worked plug on and out and lubed it up good. Problem solved.

How does the truck recognize the trailer? He puzzling part is that all of the lights work and the brakes work with the slider which tells me that all of the connections are good.