TruControl Brake Controller
March 14, 2008
Filed under Products
RV trailer-towing fans enjoy a broad selection of aftermarket brake
controls. These range from low-buck cheapies to high-end units with a
range of interesting features. All of them work, to varying degrees, but
many could be better. The new TruControl brake controller from Hensley
Manufacturing is an interesting new addition to the higher end of this
equipment segment and may well change how many RVers feel about stopping
smoothly and effectively.
Right off the top, there’s price. The TruControl is listed at $397
(msrp), which is considerably more than other brake controls that
perform similar functions. According to the manufacturer, there’s a good
reason for the price. The TruControl’s innards are all new and highly
sophisticated compared to many other such units on the market. The
powerful microprocessor-controlled mechanism offers features and
performance that should be of practical use and interest to
Most brake controls are timer-based or inertia-based. Timer-based
models ramp up the trailer brakes according to a preset amount of time
once the tow-rig brakes are applied — with no accounting for how hard
the brakes are applied. Inertia-based controllers use a mechanical
sensor to determine the rate at which the tow rig is slowing and apply
the trailer brakes in proportion.
There’s no pendulum in the TruControl. It uses a solid-state
multi-axis electronic gyroscope inertial sensor to monitor what the tow
vehicle is doing, be it acceleration, deceleration, cornering, going
uphill or downhill and so on, and uses this data to proportionately
control the trailer brakes.
The TruControl automatically detects if the trailer has electric
or the newer electric-over-hydraulic brakes and is fully compatible with
either type. It also adjusts itself to accommodate single-, dual- or
There are no gain or leveling control knobs on the TruControl. The
unit is built into a rectangular matte-black housing with an
emergency-application lever, a brake-signal indicator, three
adjustment-and-mode-selection pushbuttons and an illuminated LED readout
screen. The screen includes total braking amps or volts, percentage of
brake-power application and a configuration setting as well as setup
data such as screen-contrast adjustment and “screen off delay” that
shuts the screen off to save power when the readout isn’t needed.
Short-circuit and disconnected-circuit troubleshooting messages are also
part of the unit’s readout programming.
INSTALLATION AND ADJUSTMENT
The TruControl installs much like any other brake controller, with
four wires connecting to the tow rig, and the controller is designed to
mount where it’s out of the way, yet the LED screen is visible and the
unit is reachable to activate the emergency stop control.
While there’s no separate leveling control, as is used to change
the pendulum settings on other units, the entire housing must be leveled
prior to use. In calibration mode, the unit is tilted fore and aft
until the readout is as close to zero as possible, then the mounting
knobs are locked down.
Hensley refers to this system as using automatic gain adjustment,
but an initial driver-adjusted power setting must be dialed in.
After installation, the manufacturers’ supplied configuration
chart is used to set the initial power adjustment for your vehicle
combination in a range from 2 to 18, with 10 being the default setting.
On the left side of the chart you find your tow rig’s curb weight in
1,000-pound steps from 2,000 to 10,000 pounds. Along the bottom, the
trailer weights are listed from 2,000 to 18,000 pounds in 2,000-pound
steps. For example, if the tow rig is 6,000 pounds and the trailer is
8,000 pounds, the TruControl should be set at 9. This is just a starting
point, and is adjusted as needed for effective braking initialization,
or to suit the driver’s taste.
The above-described setting varies the power that’s sent to the
trailer brakes when the TruControl first senses a brake signal. This
initial signal gets the trailer brakes started, and the unit’s inertial
sensor takes care of the automatic-gain brake modulation from there on.
The manufacturer-supplied configuration chart gets the TruControl
set pretty close, but some user fine-tuning will likely be necessary
during the first test towing drive.
ON THE ROAD
While most inertia-based controls sense only vehicle deceleration,
the TruControl monitors and uses data from acceleration, grade and
cornering as well as braking.
Our late-model GM truck and fifth-wheel trailer-test duo started
with the default 10 configuration setting because that was where our
weight figures matched up per the setup chart. And the owner of the test
truck had miles of experience driving it with a different brand of
brake control. His TruControl experience-based feedback echoed that of
our other test driver.
We started with some around-town surface streets and rural
highways with stoplights about once per mile or so on the local
agricultural road grid. Sparse traffic and wide-open visibility meant we
weren’t causing any dangerous driving situations.
A gradual slow to a stop is velvet-smooth and seat-of-the-pants
judgment says the trailer is doing its share of the work throughout.
That fast-paced rhythmic jerking we sometimes feel while towing was
absent. Stepping it up with a simulated 60-to-0 mph emergency stop was
equally effective, as the combo displayed none of the push-pull or
herky-jerky characteristics common to widely varied braking situations.
We readjusted the configuration from 10 to 9 and resumed stopping
tests. The initial trailer reaction seemed a bit low, so we dialed back
up to 10, then reset to 11 to see what happened. We like our braking to
be a bit aggressive, and 11 seemed to do the trick. Yet, once slowed to a
near stop, the jerking common to an aggressively adjusted controller
was absent. Very nice.
Next we aimed at a short-but-steep stretch that resulted in the
combo tipped up or down, depending on which way we approached the stop.
We had no noticeable jerking or change in the brake-proportioning
balance between truck and trailer.
The TruControl comes with a 30-day money-back guarantee and a full
2-year warranty, so you’re pretty well covered if you feel it doesn’t
do the job. It’s expensive, yes, but based on our driving experience, it
delivers smooth, well-modulated braking performance that’s up to the
task of taking care of both your trailer-towing and your driving
Hensley Manufacturing Inc., (800) 410-6580, www.hensleymfg.com