How Does Curt Echo Brake Controller Know When to Apply Trailer Brakes

Updated 09/29/2025 | Published 04/24/2025

Question:

Hi, I have a 2022 GMC 3500 with integrated brake controller. Unfortunately the brake controller is not reliable. Im interested in purchasing the Curt Bluetooth brake controller for connecting to my fifth wheel. installing and Curt is easy. Question: what tells the Curt the proportional amount of power to use when applying the brakes? The in vehicle brake controller is unreliable, so the Blue power lead in the seven way to the brakes may not be relied upon.

asked by: Michael

Expert Reply:

Hey Michael, this is a really good question but basically the Curt Echo part # C79DR interprets the taillight signals that it sees and from that can tell when you are applying the vehicle brakes which then tells the inertia sensor to start looking for deceleration.

It does this by looking at the brake light circuit activation through the trailer wiring.

expert reply by: Jameson C

Jameson C.

9/26/2025

Hey Michael, did the Curt Bluetooth brake controller work out for your fifth wheel? I'm curious to know if it solved the issue with your GMC's unreliable brake controller, as it could help others facing similar challenges.

Michael

9/26/2025

@JamesonC HI, it does work, but not smoothly. Tried lots of settings, but generally found I needed to set the sensitivity high and pump the brakes hard to get the most braking power. It's really become second nature. I found that the Curt Controller does not activate the brakes when I pushed "softly" on the brake pedal. The RV brakes respond well when I pump the brakes hard. Pumping hard activates the accelerometer in the Curt, which translates into telling the brakes on the RV to work. Analogy: before vehicle brake systems kept brakes from locking up we would pump the brakes in an emergency to get a quick stop. I've learned to use that same behavior with our RV. I've wondered if how I've placed the Curt controller in my truck bed is not ideal. The Curt instructions didn't say anything about placement except that it must be firm (so there are no false positives). In my case the controller is mounted on the side of the bed where the 7-way is located--albeit at a 45 degree angle. I'm wondering if that's a factor. If I need this in my next truck I'll mount the controller square with the front of the vehicle. So am I thrilled with how it works--sort of. Installation was easy, and getting braking power in the RV does happen. I also found that while flashers do activate the brake controller, the signal is so short that no braking occurs. So I haven't needed to turn off the brake controller when I turn on the flashers (which is nice). Would I recommend this for other GMC trucks with electric over hydraulic brakes--absolutely. I've traded my Reflection for a Solitude and purchased another GMC HD truck. If I need a work around again I'll use the same Curt controller again.

Jameson C.

9/29/2025

@Michael Thanks for passing on your experience! Have you tried adjusting the sensitivity of the controller?

Michael

9/29/2025

@JamesonC I did. That was the first thing I tried. Tapping (pumping) the brakes) works well whereas just pushing on the brake without causing the needle in the Accelerometer to change just results in brake fade on the truck. Like I said though, I'd still purchase this. I think the real lesson is not to mount the controller at an angle as that takes more force for it to learn that brake power is needed.