Published 2026-10-20 · Ride On Rentals, Delta BC
How to set an electric trailer brake controller so the trailer does its share of the stopping, using the steps manufacturers and ICBC actually publish.
An electric trailer brake controller is the box under your dash, or the screen in a newer truck, that tells the trailer brakes how hard to work. Plugged in and switched on is not the same as set up. A controller set too low leaves your truck doing the stopping for both vehicles. Set too high, it locks the trailer wheels. This guide explains brake controller setup in plain terms: what the two adjustments do, how to test in the yard, how to tune on the road, and when to change it again.
Section 5.02(4) of the Motor Vehicle Act Regulations requires trailer brakes to be "adequate to maintain control" of the trailer and not to pull it off its line, and where the trailer's weight exceeds 2,800 kg, to be applied "by the driver ... from the driver's normal seated position." For electric brakes, that means an in-cab controller. A loaded dump or car-hauler trailer often lands above that line. Our BC trailer brake requirements guide has the full weight bands.
ICBC's study guide, Towing a Recreational Trailer, puts the practical side in one line: follow the manufacturer's instructions "including adjusting the RV trailer's brake sensitivity relative to that of your truck's brakes and for various driving conditions."
Almost every electric controller has the same two adjustments, under different names.
| Setting | Also called | What it controls |
|---|---|---|
| Output | Gain, power, max output | The most braking power the controller will send to the trailer |
| Sensitivity | Sync, boost, level | How quickly and how aggressively the trailer brakes come on when you press the pedal |
One manufacturer's installation guide for a time-delayed unit describes output as the control that "establishes the maximum amount of power available to the trailer brakes," and sync as the control "responsible for adjusting trailer brake aggressiveness." Its proportional units use the word sensitivity for the second adjustment. The idea is the same.
A time-delayed controller ramps the trailer brakes up over a set time once you touch the pedal. A proportional controller has a motion sensor and matches the trailer braking to how hard the truck is slowing. Proportional units usually need to be mounted and calibrated at a set angle, which is why their manuals have you calibrate them parked on level ground with the trailer plugged in. Factory-integrated controllers in newer pickups work through the truck's own menus. Whatever you have, the output-then-sensitivity order below still applies.
Before you drive anywhere:
ICBC's pre-trip steps include a note worth knowing: "If the truck has an integrated trailer brake controller, the trailer brakes may activate only if the trailer is moving at speeds of 25 km/h or more." In that case it suggests checking the trailer brakes with the breakaway pin test while parked. Pull the pin, tug gently in low gear, and the trailer brakes should hold. Put the pin back before you drive.
The manufacturer manuals we read give the same sequence. Find a dry, level, paved road with no traffic behind you. The manuals use about 25 mph, which is roughly 40 km/h.
Never adjust the controller while driving. Pull over first. The manuals also say to make changes with the vehicle stopped.
The combination stops as one unit. You don't feel a shove from behind when you brake, and you don't feel a tug or hear tires chirping from the trailer. On a light trailer the right output is lower. On a heavy one it is noticeably higher.
The time-delayed unit's guide says the output "should be adjusted during initial setup, when trailer load changes, when different trailers are used or to adjust for a change in road conditions." For a rental trailer, that means:
ICBC flags one thing for anyone installing a controller: "If your truck has an anti-lock braking system (ABS), only certain types of brake controllers can be used. They must be carefully installed to ensure that the ABS system will still function properly." Use a controller that says it is compatible with your truck and have it installed properly. If your vehicle doesn't have a controller, tell us your tow vehicle when you book and we will confirm what that trailer needs before pickup.
Not sure your hitch and wiring are ready? Our hitch classes guide explains the receiver side. For a car hauler or dump trailer, call (604) 767-7977 and ask what brakes that trailer has.
There is no single number. Manufacturers tell you to set the output on a dry, level road: brake from about 40 km/h, raise the output until the trailer brakes are just short of locking, then back it off slightly. The right setting changes with the load, so a loaded dump trailer needs more output than an empty one.
Gain (often called output or power) sets the maximum braking power the controller can send to the trailer brakes. Sensitivity, called sync or boost on some units, sets how quickly and aggressively the trailer brakes come on when you press the pedal. Set the output first, then fine-tune sensitivity.
If your truck has a factory-integrated controller, the trailer brakes may only apply once you are moving. ICBC's pre-trip test notes that integrated controllers may only activate the trailer brakes at about 25 km/h or more, and suggests using the breakaway pin test instead when stationary.
Yes. Controller manuals say to adjust the output when the trailer load changes, when you switch trailers and when road conditions change. A trailer that stops well empty can be under-braked once it is full of soil.
Questions about a rental trailer? Call Ride On Rentals at (604) 767-7977 or email [email protected].