Videos are provided As a guide only. Refer To manufacturer
installation instructions And specs For complete information.
/2 - 8 Brakes
/Electric, Electric over Hydraulic
Item # C51140
Orders above $99 qualify for free shipping
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.
Note: If your vehicle's 7-Way trailer connector has LED test lights built into it, the TriFlex brake controller will not be compatible.
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.
The above diagram shows the controls and components of the Curt TriFlex trailer brake controller.
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.
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.
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.
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.
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.
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.
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.
Video of Curt TriFlex Trailer Brake Controller - 1 to 4 Axles - Proportional
Videos are provided As a guide only. Refer To manufacturer
installation instructions And specs For complete information.
Average Customer Rating: 4.8 out of 5 stars (119 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.
by: Bill Y.09/28/2015
I installed this unit, hooked up my travel trailer and had it all calibrated and ready to hit the road in less than an hour. Took a 300 mile trip a few days later and the unit was flawless. Forget the old time delayed units, this is the way to go. Also, get the pigtail that is designed for your particular vehicle, it makes installation a snap (plug in to your vehicles available plugin and into the back of this unit) couldn't be simpler. Very satisfied with the unit and with e-trailer.com. Great products, great service. 228079
by: Tammy H.01/01/2017
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. 329228
by: Mike R.09/22/2014
Small size is convenient - easy to mount in a Tacoma. When setting it up for a single-axle 2,200-pound tent trailer with a brand new Dexter axle, I was surprised to find I have to run at the maximum output and sensitivity settings, but it works fine. 152489
by: Jeff H.08/01/2013
Items arrived quickly. Hesitant to buy "Drawtite",as I was told 'Made in China". However, it says on label 'Made in USA'! Needed additional spacer for 'middle' bolt.? Fairly easy install. Curt brake controller should be easy as well. All in all, a 'square deal! 92715
by: Lee A07/23/2013
I received my Curt triflex brake control in less than a week from ordering on line. It was so easy to put in and set up. I couldn't believe it. Just plug and play. 91176
by: Tom and Anita09/19/2016
Yes I received my order and installed the brake controller. All seems to be fine, although I have yet to tow with it yet. Here are a couple photos of the installation in my 2010 Toyota Tundra. 296409
by: Kevin L09/12/2013
So far , so good . Install took a whole 5 minutes and the overall size is easily dealt with in my Tacoma . Nice to have the led display - not too bright but easy to read and understand diagnostics and output levels . The compact size is a real bonus and it's controls are easy to understand , no complaints at all . Best is it's bracket system - screw holes to mount to the truck side are outside of the main bracket dimensions which allows a lot easier install - great intuitive design instead of trying to position , remove controller and mark holes . I was able to actually drill right past the controller in-place and install the screws , dead simple . Kudos to Curt for a great design/product . 99562
by: Joe R04/24/2014
placed into my 2014 RAM 1500 put it in place only took about a half hour with the right harness. 127226
by: Ryan R04/12/2015
Installation was easy. Product works well. The power and sensitivity adjustments are very useful. 184853
by: Bill B06/09/2014
Good buy, very easy to hook up and worked well. 134871
by: Howard S.04/06/2017
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%! 363500
by: Lyn J.03/31/2017
One of the best internet companies that I have ordered from and I have ordered a lot over the years. Kim was excellent help with my order. I elected for free ship and my order was packed and shipped out on Sat. And received on Wed. Pricing was about half of what my local trailer retailer ask. Bottom line, order from these people and you will not be disappointed. The Curt controller was very easy to install and adjust and works perfectly. The ball mount is massive, no worries about breaking this monster ! Very pleased with every aspect of this purchase. 362878
by: Joe B.11/21/2015
Easy to install and set up. I can't believe the difference between this proportional controller and the simpler time delay type. Between the power output adjustment and the sensitivity adjustment, you can quickly and easily adjust the controller for your trailer. It took me about 5 minutes to dial it in perfectly! No more jerky trailer brakes! Thank you E-Trailer! 232383
by: Mainly Dave07/22/2015
Installed and use on a 2014 FJ Cruiser. Need the wiring kit for the FJ. Installation was straight forward and everything needed was included. Took me about 2 hours but no problems. Using the unit is easy to understand. My only concern is that it does not seem to be able to lock up the brakes [even with the manual function.] But this might be due to my brakes being worn and not used recently. Have towed a fairly heavy load once [~3500 lbs,] and I am pleased with the braking function. I recommend the product. 213490
by: Mark from Pa10/13/2013
Was very easy to install. Shipped out same day. I'm very particular so install took longer than necessary about 20 minutes. I don't like having extra holes or things mounted crooked on my truck. Used it same day I installed it to haul our livestock trailer. Worked great braking was very smooth. Can't say it is better or worse than any other controller but I am happy with this one. 103662
Quick and easy to install with the included C51451 wire harness. Start to finish was less than 5 minutes. Setup and adjustment was also quick and painless. What really made the 5 star rating was their lowest price promise. After my purchase I found it for a lower price elsewhere. A quick message to etrailer was all it took, with the details of where I found it and the price, and my card was refunded the difference plus a little more! This was my first purchase from etrailer and it will not be my last. 285587
by: Greg C.08/04/2015
After talking at length (at least 15 minutes) to the rep on the phone, I choose the Curt TriFlex controller for my 2015 Silverado. It happens to be the same unit sold on Chevy's website (but cheaper on etrailor). The sales person was awesome! She wanted to be sure I got the right one, not trying to upsell me on something I didn't need. Just as she promised, it plugged right in under the dash and I even used an existing screw to mount the bracket. A 15minute install!!! I will shop here again. 216669
by: Robert A.04/21/2017
The unit with the matching installation cable was easy to install once I found the factory installed plug-in port on my 07' Dodge Quad Cab. The videos didn't have my truck model and I had to go to the Curt mfg website to find a picture of the the location of the port. I have not hooked up the truck with the trailer yet to test and adjust the brakes but the controller installation and functionality test was very easy to accomplish and went smoothly with the instructions provided. 370441
by: Doug S09/15/2013
To be honest, haven't installed yet. Have to run wiring in 2 trucks as neither has factory wiring. I want mounting to be not noticeable if I sell either vehicle. Based on reviews, and having my hands on it and the printed directions I believe it will fit my greatly fit my needs. I have a one month plus to get one vehicle ready for a road trip. LOL, I like to plan ahead. Will write more when I get working. 99999
by: frank in florida01/01/2014
Shipping was fast and product was exactly as described. It took longer to pull the factory plug from under the dash in my 2004 f250 than to complete the brake controller connections. My truck came factoy with the 7way plug and wiring installed. Adjustments were a breeze and the controller worked perfectly. 10 minutes or less install. I would recommend this to anyone. 111686
by: Sharon K06/14/2016
Bought this controller for my husband, received it on a Wednesday my husband installed that night. The very next day we left to go up state camping. Going over the mountains my husband kept saying how impressed he was with the break controller. Easy to install. He installed it in a 2006 Dodge Ram 1500, he pulls a 2016, 32 foot camper. I would recommend this product!!! 261392
by: Matt B.07/23/2015
Easy install. The product works as advertised. Installed on a 2013 Nissan Armada in order to tow our 27' travel trailer, dual axle; I had to mount the controller in a small slot below the stereo due to the fact that it would have been unsafe to install below the steering wheel. The item was small enough to fit perfectly. 213805
by: Tom H03/10/2017
The C51140 controller I purchased for my 2016 Colorado was delivered on time, and was very easy to install. Took about 1/2 hour to install, make the initial set points and dial it in so my 18' RV stops nice and smooth. I couldn't ask for anything easier. I recommend this for anyone looking to buy a brake controller. 350930
by: Jim H08/28/2015
Brake installed using the pig tail connector in 10 minutes. Initial test and it works very well. Very fast delivery and customer support was very helpful in picking out the right product for my needs. Also, I watched the video on how to install and it was spot on. Made install very quick and easy. 222302
Works perfect. Very satisfied. My only small complaint was that I read many reviews from other customers of etrailer praising the speediness of their shipping; my order showed to be "in-stock" but took nearly a week before it actually shipped. Now once it left the facility the shipping was very fast. 227310
Works perfect. Very satisfied. My only small complaint was that I read many reviews from other customers of etrailer praising the speediness of their shipping; my order showed to be "in-stock" but took nearly a week before it actually shipped. Now once it left the facility the shipping was very fast. 227309
The Curt proportional controller is versatile and effective. The wide vertical mounting orientation and self-leveling feature enables ease of installation in a variety of locations. The self-calibrating function adds to the efficiency of the controller's installation. 136217
Installed like a charm on a 2005 Dodge Ram 1500 with factory 4-wire trailer connector. Ordered the universal wiring adapter. Excellent installation instructions and videos on eTrailer made installation easy. Have yet to pull a trailer with the controller. 186154
by: Bryan H07/15/2016
Worked great. Relatively straightforward to install. The instructions were clear and I very much appreciated the installation videos on the e-trailer website. Wouldn't buy trailer wiring supplies or brake controllers anywhere else! 272278
by: Virgil R.10/31/2014
Arrived in excellent condition. In the process of installing. Will add more when installation is complete if I can. Don't really expect any problems, as have purchased other products from etrailer and always very satisfied. 158646
This is my second curt brake controller I have ordered thru etrailer. Now both trucks have curts on them. Simple and dependable. Shipping is always very fast and all my towing parts and needs will be ordered thru etrailer. 219476
by: Matt R.10/06/2013
Installed on my '05 Silverado. We pulled the rv this weekend with no problems. The controller worked as it should. My only issue was that the screws that mount the controller to the bracket were missing from the package. 102745
Product works as described. Giving it 3 because the brake intensity selector is loose and will adjust itself +/- 0.2 while im driving. Its not a big enough problem that it makes driving hazardous but its an annoyance. 371746
Have installed but not used yet. I like the slim line on this product, it take less room under the dash on my van install, less chance of a knee bump and if I do hit the knee the rounded corners should reduce injury 107182
by: John J12/09/2013
Product seems to be what I expected. I will not install the controller until we get some warmer weather up here in Michigan. Till then, thank you for the quick delivery. Ordered it Tuesday, got it Saturday. 109667
by: Gene Norris12/15/2016
Part works great, Thanks for keeping me up on sales that comes out. Great products I will keep ordering from you, when I need it. Again Thanks...................Gene ...................Roll Tide>>>>>>>>>>>> 325390
by: Dan P08/26/2013
Received purchase fast an was packaged safely. Installation was easy & plugged right up. Have hauled a full three horse trailer and with minor adjustments had smooth solid stops. Thanks, Dan 96881
by: Mark D.04/13/2017
Researched, purchased and installed a hitch and brake controller for my 2009 F-150. It was so much easier using etrailer. I have recommended them to several friends for their towing needs. 366834
Can always count on the folks at E Trailer. Products are quality, no flim flam operation her. Always more than willing to get proper fit or to correct mistakes. Who hasn't made a mistake? 341594
by: Mike B.08/29/2014
Works well so far. It was a very easy install on my 2007 Chevy Tahoe. The videos were really great. The controller arrived promptly. I appreciate the great service etrailer.com! 149234
by: Rick & Lynn05/23/2014
Great service and product! It took 25 minutes to install and the calibration was a snap! I would very much recommend Etrailer to anyone. Thanks for making this a great experience. 132035
You guys are asome order my brake controller late Friday nite and an hour later it was shipped Received it on Monday What I ordered works great already installed on truck. Thankyou 115748
by: Jonathan S04/24/2015
Product arrived as scheduled and liked the tracking access. Have not had the opportunity to install the product but will be following the direction with help from the videos 187863
Product arrived in a timely manner, seemed well packaged and took less then 5 minutes to install. will be towing 23ft camper next month and looking forward to using this. 97285
Outstanding help with ordering the correct part the first time around:) I got my item when it was promised and it was super easy to install. I'll definitely pass the word:) 236879
by: Puckett 44101/16/2014
It was so simple to install. .plug and play Just waiting on my race trailer to be completed for the driveability test..I like the compact size and it's features I l 113997
by: Chris vent04/02/2015
Fast delivery. Super easy installation. Super easy setup. I had my trailer hooked to my truck and was testing the new brake control in 30 minutes after opening the box. 182433
by: Tom R06/02/2016
Easy to set up, plug and play with the curt harness. I use it on a light weight (1500 lbs) single axel pop-up camper and it controls the electric brakes as advertised. 256168
Easy setup for my 04 yukon great price shipment was quick, perfect fit with cable connector, controls are simple to control calibrates and detects trailer quickly. 129991
by: Jason M02/08/2017
Great product, only thing I wasn't sure about was if the gain flashed while a trailer was not hooked up. I emailed etrailer and in a timely manner for a response. 341688
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