1. Trailer Brake Controller
  2. Curt
  3. Electric
  4. Electric over Hydraulic
  5. Proportional Controller
  6. Under-Dash Box
Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional

Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional

lowest price pledge
Our Price: $102.49
You Save: $25.19
Trailer Brake Controller
This item qualifies for Free Shipping
Shipping Weight: 0.64 lbs
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

Need help with installation?
Locate installers near me
Proportional brake controller automatically levels when mounted within a 90-degree vertical range and a 40-degree horizontal range. Includes digital display, 9 sensitivity settings, reverse-polarity protection, and continuous diagnostics. Lowest Prices for the best trailer brake controller from Curt. Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional part number C51140 can be ordered online at etrailer.com or call 800-298-1624 for expert service.
  • All Info
  • Reviews (454)
  • Q & A (380)
  • Photos
  • Why etrailer?

Curt Trailer Brake Controller

  • Electric
  • Electric over Hydraulic
  • Proportional Controller
  • Curt
  • Under-Dash Box
  • Up to 4 Axles
  • Automatic Leveling
  • Dash Mount
  • 90 Degrees
  • Digital Display

Proportional brake controller automatically levels when mounted within a 90-degree vertical range and a 40-degree horizontal range. Includes digital display, 9 sensitivity settings, reverse-polarity protection, and continuous diagnostics.


  • Brake controller activates trailer brakes in proportion to your vehicle's braking action
    • Automatically adjusts trailer's braking based on deceleration of tow vehicle
    • Activates immediately - no pausing like with time-delayed brake controllers
  • Automatic-leveling ability - internal sensor detects deceleration even if controller is not mounted flat
    • Position within 90 degrees up or down and within ±20 degrees side to side
  • 9 Sensitivity settings (boost settings) let you adjust initial braking power and aggressiveness
  • Triple-axis accelerometer is highly responsive, ensuring smooth, uniform stopping action
  • Continuous diagnostic check alerts you to any potential problems
  • Integrated safeguards protect your vehicle, the trailer, and the controller
    • Minimizes drain on car battery by entering power conservation mode after 30 minutes of inactivity
    • Keeps trailer brakes from overheating by reducing power output to them during prolonged stops
    • Defends brake controller and trailer breakaway systems against shorts
    • Prevents positive and negative power reversal with built-in polarity protection
  • Surface-mount technology (SMT) allows for consistent, reliable performance
    • Maximizes power output while producing minimal heat
    • Ensures superior operation in rough road conditions
  • Digital display communicates power and sensitivity settings and error codes
  • Built-in, slide-bar manual override
  • Mounting bracket and hardware included
    • Plug-in, vehicle-specific brake control adapter (sold separately) can be used for certain applications to reduce installation time


  • Application: trailers with up to 4 axles (8 brake assemblies)
    • Designed for use with electric or electric-over-hydraulic trailer brakes
  • Dimensions: 3-1/4" wide x 4" long x 7/8" tall
  • Mounting:
    • 90-Degree vertical plane operating range
    • 40-Degree horizontal plane operating range
  • Limited lifetime warranty

Note: If your vehicle's 7-Way trailer connector has LED test lights built into it, the TriFlex brake controller will not be compatible.

Proportional Braking

With a proportional brake controller, you can get heavy-duty emergency braking, general braking, or slow-to-an-idle braking for your trailer automatically. The intensity with which your trailer brakes are activated and the rate at which they are applied are dependent on the deceleration of your tow vehicle. This means that, unlike time-delay controllers - which send the same amount of preset power to your trailer brakes every time - proportional controllers are able to adapt to every braking situation differently. So, if you slam on the brakes in your truck, your trailer brakes will activate with that same extreme intensity. And if you merely slow down as you approach a red light, your trailer will gradually brake in the same manner. Just set the initial power level, select a sensitivity setting, and you're good to go.

As long as the TriFlex controller is properly mounted as indicated in the instructions, it will sense - via an internal inertia sensor - how your tow vehicle brakes. This triple-axis, inertia-based sensor responds to the deceleration of your tow vehicle as you brake by signaling the controller to send out enough power to your trailer brakes so that they are activated with an intensity that matches. The result is uniform braking across your towing setup. No push-pull action - just smooth, proportional braking every time.

Built-In Controls for Adjustable Power

Curt TriFlex Controls and Components

The above diagram shows the controls and components of the Curt TriFlex trailer brake controller.

  1. Digital display
  2. Thumbwheel power output control
  3. Sensitivity adjustment switch
  4. Slide-bar manual override

Output Control

During the initial setup process, use the thumbwheel on top of the TriFlex to adjust the output. The output control lets you set the maximum amount of power that will be applied to your trailer's brakes. Typically, the output is only readjusted when you experience changing road conditions or if you switch over from a heavy, loaded trailer to a much lighter, empty trailer, or vice versa. To get more power to your brakes, rotate the switch to the right. To decrease the power output, move it to the left. The output setting will appear on the digital display when you press the brake pedal or activate the manual override.

Sensitivity Settings

Once you have the overall power set, you can fine-tune the power output by adjusting the sensitivity of the internal sensor. Use the switch on the side of the TriFlex to achieve your desired degree of intensity.

Move the switch toward you to boost the power output, causing your trailer brakes to activate with more intensity right off the bat. This means that they will also reach maximum braking faster simply because they will start out at that higher intensity. This is particularly beneficial if you are towing a heavy load because the intensity required to stop that load may be far greater than that needed to halt your vehicle. Therefore, sending out more initial power to the trailer brakes - and causing them to reach maximum braking faster - allows you to better control the trailer so that it doesn't push your tow vehicle before coming to a complete stop.

There are 9 sensitivity levels (boost levels), with 1 being the least sensitive. At level 9, the sensitivity of the internal sensor is as high as it can go. When you change the setting, the display on the TriFlex will flash the level before reverting back to showing the power output.

Safety Features

The TriFlex offers advanced safety features to prevent damage to various components of your towing setup. When the TriFlex is not in use, it will be in power-saving mode, reducing the power draw to minimize drain on your vehicle's battery. This power-conservation mode begins after 30 minutes of inactivity and ends the moment your vehicle's brake pedal is pressed.

When you stop at red lights, or any time that your truck and trailer are at a standstill with the brakes applied for a prolonged period of time, the TriFlex will reduce the power output to your trailer's brakes, preventing them from overheating.

If ever there is a time that you need to brake your trailer separately from your tow vehicle, the manual override lever is easily accessible. Pushing this slide engages the brakes on your trailer with either full power or the maximum power allowed by the output level, depending on which setting you select. In addition, when you activate this override, the brake lights on your trailer will illuminate, properly warning those behind you of the braking action of your rig.

Automatic Leveling and Simple Installation

The self-leveling feature of the TriFlex ensures that the brake controller continues to function even as you drive up steep hills or through the mountains. Simply mount it in your cab at a vertical angle that is within 90 degrees, and the controller will level itself automatically. Make sure that the controller is also positioned so that the side-to-side angle is within ±20 degrees.

Installation is a snap. After mounting the TriFlex unit in your cab using the included bracket, hardwire one end of the included pigtail harness directly into your vehicle. The other end plugs into the brake controller. To transfer the TriFlex to another vehicle or to remove it for storage, just unplug the unit and remove the screws that hold it place in the bracket. Curt offers a spare mounting bracket (C51144 - sold separately) that can be used to affix the TriFlex in your other automobile.

Installation Accessories

For even easier installation, a vehicle-specific wiring adapter (sold separately) is available for most newer trucks and SUVs. One end of the custom adapter plugs into your vehicle, and the other end plugs into the controller - no hardwiring required.

Note: If a custom brake control wiring adapter is not available for your vehicle, one of the following will be required:

20-Amp circuit breaker (9506P - sold separately) for 2- to 4-brake applications

30-Amp circuit breaker (38630 - sold separately) for 6- to 8-brake applications

See also etrailer.com's exclusive 7- and 4-way brake control installation kit (ETBC7 - sold separately) if you don't already have a 7-way plug at the back of your vehicle.

Surface-Mount Technology

Curt's TriFlex brake controller is built using surface-mount technology (SMT). This method of construction involves soldering electronic components directly to the surface of a printed circuit board. SMT eliminates the need for leads, which are used in older through-hole technology. The result is a circuit board that is smaller yet provides more routing area and that offers superior performance, reliability, and durability.

Curt SMT Circuit Boards

Circuit boards constructed using SMT have been shown to perform better under rough conditions with excessive vibration than those made using the through-hole method. And where would vibration be more likely to occur than in towing applications? SMT circuit boards also produce less heat, leading to increased durability and longer life. In addition, lower levels of resistance ensure better performance, especially for parts that operate at higher frequencies.

Each Curt circuit board is made using high-quality components that are pieced together in the most technologically savvy fashion, leading to greater predictability and reliability in functioning.

51140 Curt Tri-Flex Proportional Trailer Brake Control

Item # C51140

Installation Details C51140 Installation instructions

California residents: click here

Customer Reviews

Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional - C51140

Average Customer Rating:  4.7 out of 5 stars   (454 Customer Reviews)

Proportional brake controller automatically levels when mounted within a 90-degree vertical range and a 40-degree horizontal range. Includes digital display, 9 sensitivity settings, reverse-polarity protection, and continuous diagnostics.

- C51140

Fairly easy to install and set up. I set it up in a 2013 DODGE Durango and pull a 5200# camper with electric brakes. Stopping is very smooth and controlled.

Still like it
Bill A - 04/07/2021

- C51140

Great controller! Easy to adjust even on the fly. I had the controller adjusted a little aggressive and as I was trying to get out of Buffalo to go south for the winter we ran into some snow accumulation and was able to quickly dial back the controller to avoid locking up on thick snow covered roads. Literally a potential disaster! Very happy with the controller

- C51140

this product nearly killed me. in February of 2020 I was towing from Philadelphia area to Miami. Getting off the ramp of 95 at S.O.B. I depressed the slidding button for added braking and I heard a tiny snap and the button stuck in. we skidded to a stop and put flat spots on out tires. turns out the return spring inside snapped off its tiny plastic tab and the brakes locked on. cheap [foreign] crap strikes again. when will we pleas make this stuff in amarica again ??

Andrew S - 10/01/2021

- C51140

Worked as desribed,I had no problem installing after watching video.After taking fuse box cover off my wires were hooked up already,no work to do there.For me a straight up easy install that seems to work great.Drove 130 miles after install ,no issues.

- C51140

Great product.Works as described. The instructions were well written and video was helpful as well.Would recommend to anyone looking for a good break controller.

Works great.No issues so far other than the little light that lets you know its on.Wish I could shut it off.My truck sets a long time between starts so it probably helps drain the battery a little.Great product and instructionsvideo,easy to install.I would by it again if I ever need one.
Monty - 09/17/2021

The Curt Triflex does have an indicator light that will stay on for several minutes after the vehicle has stopped running. It eventually will go into sleep mode after a period of time. The light pulls such little power that will not drain the battery so you don't have to worry about that.

-- Etrailer Expert Heather A - 9/29/2021

- C51140

I used one of these controllers for about 7 years before it died...this new one didn't make it to the first trip! This controller died on testing right after installation, initially indicating an overload on the trailer the first time I activated it. After this first message, it constantly indicated that it was hooked to a trailer or that there was an overload condition, even when not hitched up! I could not get it to reset, even after being disconnected for days. I checked my trailer and everything is fine...I spent a lot of time looking for a problem that didn't exist. The new Tekonsha is working fine, so I guess the Curt was a bum controller from the factory. This isn't etrailer's fault at all; I have nothing but things to say about them!

- C51140

Easy to set up and operate. The controls are less than intuitive. There’s a sensitivity dial and a force level slider that seem to affect the application of the brakes. It’s not exactly clear which one is more important or has the most impact. The unit works well at highway speed but at low speed operations seems to apply the brakes aggressively to the trailer. This is my first experience with a brake controller so can’t compare with other units. It does make parking lot operations somewhat clumsy. It definitely gets the job done though.

Poorly. The tekonsha prodigy is so much better than this unit.
Jason J - 06/25/2020

- C51140

The TriFlex Trailer Brake Controller is just what I needed, it is small, easy to install, simple to operate and gets the job done. If you are looking for a brake controller with fancy displays and flashing lights the TriFlex may not be right for you. The TriFlex is all business and will provide excellent proportional braking. I installed my controller on my F150; I use the truck to tow a 26 foot, 3,500 travel trailer. The truck and trailer both work together with the controller to deliver a superior braking experience.

- C51140

Watched one of your installation videos. With the factory wiring harness adapter, that came with the Curt Tri Flex controller, installation was a breeze. It took longer to decide where to mount the controller, than it did to make the electrical connections. Used it with my tent trailer on a 2 day trip, worked perfectly. Very pleased with performance and price. See attached photo of finished installation.

- C51140

This is the second product I have bought here - this unit goes in as described and follow examples on the site you’ll not have an issue. Provided that your vehicle wiring is correct and without faults - expect it to work straight away. Mounting the bracket simple and the wires tuck under the carriage. 5 min install. Now there’s a little learning curve to adjust dependent on the trailer. Thanks e-trailer again for the right stuff! (2002 GMC truck)

- C51140

This controller works perfectly. Although it does have a slight hesitation when you take your foot off the brakes. And you don't have to have it perfectly mounted level. I mounted it under the dash in my Chevy Colorado and have had no problems with it whatsoever it works very well with my small travel trailers electric brakes.

- C51140

Did the job. No complaints. Everything in order and all necessary cable ties etc. I was connecting to a 7 point connector and therefore fed it through the body (already a hole for cables that can be used) under the vehicle as opposed to only hanging through the closed back hatch per one of the videos.

Still ok, but would be nice to have a little more adjustment in the unit to tilt up or down or to unplug easily when not in use and want out of the way. But not a deal breaker.
Evan - 06/14/2021

- C51140

Overall it has been working great. Easy install and programming. Occasionally it fails to connect at the first time plugging in but usually unplugging the trailer and plugging it back in solves the problem. Only had to disconnect power from it a couple times to solve the connection issue. I’d recommend it to a friend. *installed on a 2012 Tacoma

- C51140

I bought a 7 pin trailer wiring/brake connection for my Dodge pickup. I installed it myself, the instructions were absolutely clear and correct. It was an easy installation. In the year since, I've pulled my trailer (tandem axle, 16') many times. The brakes continue to work perfectly as well as the lights. The connectors are solid, all work just like new. I recommend Etrailer parts and their people 100%!

Still using the products no problems, everything’s works great.
Howard S - 04/06/2018

- C51140

Pretty easy to install after watching the how-to videos. Plus, our Grand Cherokee came pre-wired for towing from Jeep, so it was even easier. Jeep issue (no fault of etrailer): I did have to go to the dealer to pay them to "enable" the manufacturer installed tow wiring. Annoying that it doesn't work by default.

- C51140

Great service from etrailer, I have not used product yet but will in near future.

The brake controller works perfectly, great product!
Jay M - 07/30/2021

- C51140

So I installed the brake controller but my trailer is in the repair shop for a lengthy stay and I have not been able to actually use it. I would mention though that the digital readout is not has sharp and clear as portrayed in pictures. That is my biggest disappointment at this time.

- C51140

Works great, installed easy with the wiring harness adaptor. Etrailer.com delivered as promised again. Thanks.

After a year and countless camping trips, this thing has worked flawlessly. It was easy to install, and wire. Would definitely buy again.
Micheal c - 08/06/2021

- C51140

I thought the wrong pigtail was sent but after Stacey sent me the link to the video everything was correct and the installation was super easy. I was looking at the wrong plug under the dash, mine is hidden behind the panel. etrailer has been very helpful in the past on products I bought. Thank you

- C51140

Installed curt triplex brake controller today. Was able to do it by following your video on installing controller. Very happy with product and installation. Sure I saved at least as much as I paid for product by installing it myself. The install was a lot easier by using prewired plug in for Silverado with tow package. Thanks

- C51140

Installation was easy with Adapter cable and Controller which I installed on top of dash board cover and required only one hole to be drilled. Installation location allows for easy access to adjust settings, apply the trailer brakes alone and see the display. Tough part was locating the 2010 Ford F53, Wennibago, Vista, OEM connector which was out of sight. Remove the dash board cover, which was easy, then look for the big harness (see pictures) and the smaller cable which splits away from it. None of the literature explained that the connector is gray for six pins although only for pins are in the connector. Once found, just plug things together and it all works.

- C51140

I connected the Curt Brake controller into my 2007 Toyota 4runner. It took 5 minutes to hook up using the curt wiring adapter for my vehicle. I pulled a 16' aluminum stock trailer with one horse in it. There were no problems with braking and the braking action was very smooth on the trailer. I also have a weight distribution on the trailer which helps with using the Toyota in an "emergency" tow. The horse had an easy 3 hour tow with smooth braking and no swaying. Thanks etrailer for all the tools that make farm life easier.

- C51140

Produce arrived the next day and was installed that day. Great customer service. Highly recommend! Purchased trailer controller for a rv camping trip.

- C51140

Easy install especially with the colour coding for the pigtail to the 2016 Colorado wiring in the kick panel. Have not hooked up to a trailer, so cannot comment on the performance of the Curt Triflex trailer controller.

- C51140

Works well and not a bad install with the etrailer videos, my 97 Dodge Ram Sport 1500 5.2 is a””Wood” truck so I installed the truck flex where the ashtray was, works well

Show More Reviews

Ask the Experts about this Curt Trailer Brake Controller

  • Where Is the Brake Controller Plug on a 2008 Dodge Ram 1500
    The correct brake controller adapter plug you are looking for is blue however, it will only have four pins as you mentioned which means the one you have located in not correct. The correct plug you will be looking for and can find in the attached photo is located to the left of the intermediate shaft on the steering column. This plug can also be seen in the attached video. The correct adapter for you if you have a Curt brake controller like the Curt TriFlex Trailer Brake Controller part...
    view full answer...
    Image 1 for
  • Harness Needed To Install Curt Brake Controller On a 2015 Chevy Silverado 1500
    In order to install a Curt TriFlex Trailer Brake Controller part # C51140 on a 2015 Chevrolet Silverado 1500 you'll need the Curt Custom Wiring Adapter for Trailer Brake Controllers part # C51451. It will indeed plug into a port under the dash making for a no-splice install.
    view full answer...
  • How To Install Curt Brake Controller On 2018 Jeep Cherokee with Tow Package
    The Curt TriFlex Trailer Brake Controller part # C51140 with Curt Custom Wiring Adapter for Trailer Brake Controllers part # C51459 is an excellent option for a 2018 Jeep Cherokee with tow package. The brake controller will mount on the dash within reach and then the custom adapter will plug into the rear of the controller and then the tow package port on the vehicle which is located underneath the dash, just to the left of the steering wheel, taped to another harness near the emergency...
    view full answer...
    Image 1 for
  • Can Curt TriFlex be Used With 2019 Toyota Highlander
    So long as your 2019 Toyota Highlander does not have the factory tow package, you can use the Curt TriFlex Trailer Brake Controller # C51140 you referenced. To use it you will need the Wiring Adapter # C51515, T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118449 and Universal Installation Kit for Trailer Brake Controller # ETBC7. If your '19 Highlander has the factory tow package I strongly recommend the Curt Echo Mobile Trailer Brake Controller # C51180 because it...
    view full answer...
  • Recommended Out of the Way Brake Controller for 2009 Ford F-150 With Factory 7-Way
    The Curt TriFlex Trailer Brake Controller # C51140 with Wiring Adapter # C51436 is a very good option for your 2009 Ford F-150, though to mount it you will need to use the included mounting bracket and screw it in under the dash. If you (understandably) don't want a brake controller unit in the cab of your F-150, you do have a great option I recommend checking out, the Curt Echo Mobile Trailer Brake Controller # C51180. The Echo is the best option because it will simply plug into...
    view full answer...
  • Brake Controller Installation on my 2017 Audi Q7
    With the Curt Triflex part # C51140 and the Curt Adapter part # C51522 you will have all you need to successfully install your controller. I have linked a video for you showing the operation of the controller. Check it out to familiarize yourself with it.
    view full answer...
  • Troubleshooting Curt Triflex # C51140 Issues After Unit Overheating
    First, check the display on your Curt Triflex # C51140 for any error codes that come up with applying the brakes with your trailer connected. If you get an error code, you can reference the user guide to find a potential solution. If you don't have any error codes showing on the display to help you diagnose the issue, I would start by checking the wiring on your vehicle and on your trailer, particularly the blue brake output wire. Check the wires for any signs of damage such as exposed...
    view full answer...
  • Parts Needed to Install Brake Controller on 2013 Toyota Tundra with Factory Tow Package
    The only thing you'll need to install the Curt # C51140 TriFlex brake controller on your 2013 Toyota Tundra is the # C51362 vehicle-specific brake controller wiring harness. As long as the vehicle is equipped with the factory tow package, you won't need anything else. The TriFlex controller includes the necessary bracketry and hardware for installation. The factory tow package connector that the harness plugs into is located to the left of the e-brake pedal, above the kick panel as shown...
    view full answer...
  • Troubleshooting Curt Triflex Brake Controller that Won't Power On Installed on 2018 Ford F-150
    The install harness part # C51436 is the correct harness to install the Curt Triflex part # C51140 in your 2018 Ford F-150. What I would do is verify the controller wiring has power on the black wire as this is the power circuit for it. You'd want to use a circuit tester like part # PTW2993 for this. If there is no power there then check under the hood for a blown fuse for the brake controller power circuit. If there is power there then you most likely have a bad brake controller as with...
    view full answer...
  • Troubleshooting Electric Over Hydraulic Brakes Not Activating of Vehicle
    It sounds like there may be an issue with the wiring in the trailer to the hydraulic brake actuator. When you installed the Adapter Module # DX35FR you did receive the trailer connected message. I have attached the instructions for the Adapter Module that shows several different wiring schematics for the popular hydraulic actuators. If yours is not listed let me know and I will help you find the correct wiring. It sounds like there may be issue with the power wire that is going...
    view full answer...
  • How do I Install The Curt Triflex in my 2000 Chevrolet Aatro Van
    To install the Curt TriFlex Trailer Brake Controller part # C51140 you will use the Universal Wiring Adapter for Curt Trailer Brake Controller part # C51515. This will get connected to the Universal Installation Kit for Trailer Brake Controller part # ETBC7 to get the signals to the back of the vehicle for you. This is assuming your have a working four pole already there. If you do not add the Curt Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part # C55411 to have the starting...
    view full answer...
  • Install Harness for Curt Triflex in 2018 Dodge Durango
    The Curt Triflex part # C51140 does not come with a custom fit harness for your 2018 Dodge Durango so you'd need to order that separately with part # C51446 and you'd be set.
    view full answer...
  • Harness Needed To Install Curt TriFlex Brake Controller On 2021 Ram 1500
    In order to install the Curt TriFlex Trailer Brake Controller part # C51140 on a 2021 Ram 1500 you'll need the Curt Brake Controller Adapter Harness part # C51458.
    view full answer...
  • Curt Brake Controller Adapter For 2019 Ford Expedition
    I am happy to help you install the Curt Triflex part # C51140 in your 2019 Ford Expedition with a factory 7-way. I recommend to use Curt Custom Wiring Adapter for Trailer Brake Controllers part # C51436 to install the brake controller. It will plug into a built-in port under the dash of the Ford and the other end plugs into the brake controller to power the brake output circuit on the 7-way to tow a trailer with brakes.
    view full answer...
  • How To Use Curt TriFlex Trailer Brake Controller On a 2018 Ram 1500
    The Curt TriFlex Trailer Brake Controller part # C51140 is an excellent option for a 2018 Ram 1500. That said, you'd also need the Curt Custom Wiring Adapter for Trailer Brake Controllers part # C51458 for plug-in-play installation. In regards to the factory brake controller, these aftermarket options are much more reliable and offer better performance. There is really no comparison and many swap out the factory brake controller for an aftermarket brake controller.
    view full answer...
  • Curt 5140 Brake Controller Troubleshooting Reading Voltage Numbers without Trailer
    Most likely it's just corrosion on the trailer wiring connector confusing your TriFlex part # C51140 into thinking that a trailer is connected so first try cleaning that. If not this controller is prone to internal bugs so you might try unplugging it and plugging it back in to reset it.
    view full answer...
  • Troubleshooting Two Dashes on Curt TriFlex Brake Controller Display
    On the Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional # C51140 the double dash display means you have a power issue. It can be that you are not getting 12V to the controller, or it can mean your ground connection is bad. You will want to check your brake controller wiring. White is ground and black is 12V power. You can use a circuit tester like # PTW2993 to test these wires.
    view full answer...
  • Is Wiring Harness/Adapter Needed to Install Brake Controller on 2017 Chevy Colorado
    The 2017 Chevy Colorado doesn't use a plug-in connector, but it does have a tow package wiring harness under the dash that the controller would wire directly into. The harness is located behind the driver's side kick panel. The controller would install as shown in the linked video. The pigtail included with the Curt # C51140 TriFlex brake controller would wire up to the tow package harness as follows: • Tow Package Red/Green wire connects to Black wire from brake controller pigtail •...
    view full answer...
  • Installing the Curt TriFlex Trailer Brake Controller on a 2017 Chevrolet Colorado
    I am having a hard time trying to understand your problem so bear with me here but it sounds like you are trying to install the Curt TriFlex Trailer Brake Controller part # C51140 on your 2017 Chevrolet Colorado with the Universal Wiring Adapter part # C51515. If that is the case then you are off to a great start as this is the correct harness for your Colorado. If your Colorado came with a factory 7-way then the wires you need to attach the harness to are already ran underneath the...
    view full answer...
  • Location of 7-Way Tow Package Wires on a 2005 Chevy Tahoe to Install a Brake Controller
    If your 2005 Chevy Tahoe did not come with a factory installed 7-Way trailer connector then you will need to add one using # 30955 which plugs into a connector located above the spare tire under the vehicle. I have included a picture that shows what it looks like for you. If your Tahoe doesn't have that round connector above the spare tire then there would be a wire bundle instead in the same location. And if your Tahoe came with a factory 7-Way then there is no other connection you...
    view full answer...
    Image 1 for
  • Brake Controller Wiring Location on 2008 GMC Canyon with Factory 7-Way
    The brake controller wiring on your 2008 GMC Canyon is actually hiding under your dash. It will be to the left of the steering column and above the brake pedal. This can sometimes be difficult to find, but, you'll know it because it will be held together by a white tag. If you take a look at the linked install video of a brake controller being installed on a similar model year Canyon you can see where you need to look. You will then be able to wire in a brake controller on your 2008...
    view full answer...
  • Recommended Brake Controller Wiring For 2017 Hyundai Santa Fe
    There is no brake controller harness on your 2017 Santa Fe so it will require some hardwiring. First, you will need part # ETBC7. This plugs into the 4-way connector on your Santa Fe. You will then need to run the additional wires to complete the installation of the brake controller. I have attached a drawing that shows how the wiring is run for the # ETBC7 and the brake controller. The Curt TriFlex Brake Controller, part # C51140 is a proportional controller that will apply the...
    view full answer...
    Image 1 for
  • Troubleshooting Curt Triflex Brake Controller Showing OL Code on Display
    The Curt Triflex brake controller is known to have more problems than other brake controllers so I would not rule out the problem being the controller. Testing the brake controller is fairly easy. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like the Quickee Tester, part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates...
    view full answer...
  • Installing a Brake Controller in a 2013 Chrysler Town and Country with Factory 7-Way Connector
    It is possible that the wire you found is for a brake controller. What you can do is use a separate 12 volt battery and apply power to the pin in the 5 o'clock position on the 7-Way connector on your 2013 Chrysler Town and Country. Then have someone use a circuit tester such as # 3808 to test that wire. If that is the right wire then there would be power on it when performing this test. Officially, a brake controller has to be hardwired to your van because there isn't a plug-in harness...
    view full answer...
  • Troubleshooting Curt Brake Controller Triflex that Shows Flashing 0.0 on Display without Trailer
    The Curt brake controllers are notorious for needing to be reset frequently to get rid of bugs like you described. Try unplugging the harness from the back of the controller and then plugging it back in to see if that takes care of the issue. I'd recommend going to a more reliable controller though like the iCommand part # 5535 as this is a very solid option.
    view full answer...
  • Testing the Curt Triflex Brake Controller for Power
    I recommend putting a tester on the 5 o'clock pin of your 7 way connector on your FJ Cruiser. This is the brake controller pin. Hit the manual override and see what your readings are. The Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional # C51140 is a proportional controller so only the manual override can be tested accurately when still using a multimeter like # PT89ZR. I've attached a troubleshooting article to assist.
    view full answer...
  • Troubleshooting Curt Voyager Brake Controller Not Functioning on 2018 Ram 1500
    The issue is that the newer Ram trucks use a different style of brake signal that the Voyager you have is not capable of interpretting. Not every brake controller can be used on your truck for this reason and that's why yours can't tell that you are applying the brakes. You'll have to go to a controller from Curt that can be used on your truck like the Triflex # C51140 which is a proportional controller that would work well.
    view full answer...
  • Brake Controller Installation-2013 Acura RDX
    The Acura RDX doesn't have the provision for plugging in a brake controller. The controller would need to be hardwired using our Brake Controller install kit part # ETBC7 and the Curt pigtail, part # C51515. To install the 7-way trailer connector, a functional 4-pole trailer connector is needed. You can install one using part # 118569. The 4 pole to 7-way adapter provided with the ETBC7 kit will plug into the 4-pole, and will have 4 remaining wires that need to be connected. Ground the...
    view full answer...
  • Troubleshooting Curt Triflex Brake Controller that Is Flashing Numbers Randomly without Trailer
    Sounds like you have a bit of corrosion on the brake output pin of the 7-way you have on your tow vehicle. Try cleaning the pin in the 5:00 position and should see that issue go away. When a trailer senses an amperage draw (which corrosion will provide) it will think a trailer is connected and show an output setting. Also the TriFlex is known to be a bit buggy so you might also try a hard reset by unplugging it and plugging back in. I attached a link to the install instructions/manual...
    view full answer...
  • Which Trailer Wiring Harness is Needed to Install Curt Triflex in 2020 Chevy Silverado 1500
    The Curt TriFlex # C51140 that you have can be used in your new 2020 Chevy Silverado 1500 but you will need a new harness as there where some changes between the 2017 and 2020 models. So what you'd need is just the part # C51525 and you'd be set!
    view full answer...

Do you have a question about this Trailer Brake Controller?

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality trailer brake controller for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer brake controller information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Joe V
Test Fit:
Joe V
Employee Nicholas E
Test Fit:
Nicholas E
Employee Rick A
Test Fit:
Rick A
Employee Shane T
Test Fit:
Shane T
Employee Randy B
Test Fit:
Randy B
Employee Brent H
Test Fit:
Brent H
Employee Shane H
Test Fit:
Shane H
Employee Ryan G
Test Fit:
Ryan G
Employee Leah B
Edited by:
Leah B
Employee Mike L
Expert Research:
Mike L
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee John H
Expert Research:
John H
Employee Adam R
Expert Research:
Adam R
Employee Rachael H
Expert Research:
Rachael H
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Andrew K
Video by:
Andrew K
Employee Dustin K
Video by:
Dustin K
Employee Lindsey S
Written by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Andrew L
Video Edited:
Andrew L
Employee Kathleen M
Video Edited:
Kathleen M
Employee Sue W
Video Edited:
Sue W
Employee Chris R
Video Edited:
Chris R
Employee Zach D
Video Edited:
Zach D
Employee Adele M
Updated by:
Adele M
Employee Wilson B
Updated by:
Wilson B
Employee Amanda M
Updated by:
Amanda M
Employee Kristina F
Updated by:
Kristina F
Employee Isabelle B
Updated by:
Isabelle B

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.