DirecLink Brake Controller

[rgevans871]

Has anyone used the DirecLink Brake Controller and if so, how does it compare to your previous brake controllers?

Ron

[RustyJC]

Never heard of it. Got a link to a website???

Rusty

[rgevans871]

The website is DirecLink.com.

[RustyJC]

Reading their limited technical information, it sounds like a "gee whiz" time-based controller that generates a braking application curve when it senses that the brake lights on the tow vehicle have come on. Without sensing the tow vehicle's brake system pressure (as do the BrakeSmart and MaxBrake controllers) or brake pedal position (as did the Jordan Ultima 2020), the controller has no way of sensing the decelerative effort that the driver is requesting through the tow vehicle's brake pedal. The inertial controllers (such as the Prodigy) attempt to do this using a pendulum or an accelerometer, but this is an indirect measurement of the requested level of deceleration that doesn't take into account wet or icy roads, gravel or sand, etc., but DirecLink's technical writeup says that they don't use this technology.

I guess I'd be interested to know just what these data points are that the DirecLink controller purports to sense in the following statement from their website:

Quote:

When you apply the brakes, DirecLink uses multiple data points in a proprietary way to determine the proportional level of trailer braking.

Rusty

[Paul R. Haller]

I, like Rusty, would want to know more. I had an old Reese controller on my first rig. It was just awful and after an incident always left me with a major pucker factor. The time based controllers are just plain dangerous, you slam on the brakes because the guy in the next lane crept over into yours and there is nothing, no braking at all with that big 5er pushing you forward... as you begin to pucker knowing this will turn out badly, they kick in at the last second. I ripped it out and put in a direct sensing controller.
-Paul R. Haller-

[TXiceman]

Wow, they want $295.00 for this whiz-bang "network Computer" controller. I don't know what data they are getting from the vehicle computer that could be used in the braking system, other than the brake light is on. It appears to be another try at programming based on the time and deceleramator based controller.

To justify the high price they have tacked on the ability to read the transmission temperature on some vehicles. For $55.00 more you can get a MaxBrake and have true proportional based controller based on the braking pressure.

What bothers me about these controllers is you are depending on the programing as perceived by a techno-geek that has probably never pulled a trailer.

I like some others have had the pucker factor max on on a wet street when the truck slides, and you have zero deceleration and a 13000# trailer (with no braking force trying to push the truck and it is trying to jack knife. That controller (a Prodigy) made it's last trip.

Ken

[Randy the sly old fox]

Wait a second, I don't believe that this is just another fixed curve output device. Modern cars and trucks have many different computers and sensor systems all linked together by a high speed serial bus structure (similar to USB, but more robust). Since all sensor signals travel on this bus it is easy to detect wheel rotation data from the anti-lock brake sensors - vehicle speed, engine RPM, transmission gear and even brake position. This controller could be as good as - or even better than the integrated controllers. I recently downloaded the electrical manual for my 07 Silverado HD and learned that the actual brake controller module is located in the frame rail just behind the wheel well - I am not sure what the computer there actually does - but it is connected to the computer bus.

[RustyJC]

Unless any of us are privy to the "proprietary algorithms" this manufacturer claims to use, all we can do at this point is speculate how the black box decides what signal to send out on the blue wire.

AFAIK, the only actual brake system parameters available on a vehicle's data bus are (1.) brakes on or off and (2.) engagement of the anti-lock brake function. If there's a pressure transducer measuring brake system hydraulic pressure or a potentiometer measuring brake pedal position, I'm not aware of it.

So, with that said, here's my 2 cents' worth of speculation. If I were designing this controller, in addition to brake application, I would take vehicle speed as another key variable in generating an output braking curve - more aggressive braking at highway speeds; less aggressive in stop-and-go driving (just like we had to adjust the gain on the old time-based controllers).

That's why I said that it looked like a "gee-whiz" ramped time-based controller. Is it better than the old Reese or Draw-Tite controllers many of us used? Very likely. Is it as good as a BrakeSmart, MaxBrake or Jordan Ultima? Not very likely.

JM2CW. YMMV.

Rusty

[Randy the sly old fox]

There has to be more than that on the bus - I know that OnStar counts the wheel turns and converts to distance - it can also detect how hard the wheels are turned - right or left - this way it can maintain its turn by turn directions without GPS.

[RustyJC]

Oh, there's a ton of information on the bus - on my truck, there's transmission temperature, exhaust gas temperature (3 different readings), and more stuff than I could list for the rest of the day.

In my post, however, I was just referring to information that was directly relevant to driver input to the tow vehicle's braking system and, in the absence of that, what else might be used in this manufacturer's algorithms to establish trailer brake output.

Rusty

[Randy the sly old fox]

Well lets see you might also want to know vehicle speed, throttle position, wheel slip/skid, amb temp, as well as brake on or off.

An algorithem is nothing more than a formula whose output is based on the state of many different inputs.

So let's see - throttle OFF+ brakes ON+ Amb Temp 30+Wheel Speed 0 MPH=Huge Pucker

[RustyJC]

Quote:

Originally Posted by RustyJC If I were designing this controller, in addition to brake application, I would take vehicle speed as another key variable in generating an output braking curve....

Ummmm, yep. I suggested that one in post #8 above as well as anti-lock brake status (wheel slip/skid).

Quote:

Originally Posted by Randy the sly old fox So let's see - throttle OFF+ brakes ON+ Amb Temp 30+Wheel Speed 0 MPH=Huge Pucker

Or it could be nothing more than sitting at a stop light on a cool, sunny day with dry roads. That's my point - the controller can infer, but those inferences are based on incomplete data and could likely be erroneous. That's what the driver's brain and right foot takes into account in the desired brake application, as measured by the brake sensing controllers I mentioned earlier. Maybe it's just me, but I want the trailer brakes to do what I tell them to do, not what someone else thinks they should do under a given set of inferred conditions and has programmed into the controller.

Maybe someone should buy one of these things (or better yet, get it on a freebie product evaluation basis on behalf of iRV2), try it out and report back.

Rusty