Theory of Operation
The Integrated Trailer Brake Module (ITBM) communicates with the vehicle through the high speed CAN C bus. The ITBM monitors the Brake Pedal Status, Vehicle Speed and ESP status via CAN message. It also outputs the Trailer Status, Gain Setting, and Trailer Brake Output Power to the vehicle. The ITBM connects to the electric trailer brakes through the 7-Way connector and controls the brake force through a Pulse Width Modulating (PWM) duty cycle.
Note. If there is no trailer connected there will be NO Pulse Width Modulating (PWM) signal.
The PWM is proportional to the rate of deceleration measured by the accelerometer inside the ITBM. The ITBM controls the PWM output to the trailer brakes in four ways. The first occurs while the brake pedal becomes active and vehicle speed is greater than 0 km/h (0 mph). The second is the manual lever on the ITBM that can be controlled by the driver. If both the manual lever and the brake pedal are active simultaneously, the greater of the two, in terms of PWM output, will prevail. The third is after the vehicle has stopped moving, after approximately three seconds of the brake pedal applied the trailer brakes will be applied too. This is to minimize hitch to trailer noise and vehicle roll back when taking off from a stop and on an incline. The fourth is that it will become active during an ESP trailer sway event.
The Integrated Trailer Brake Module (ITBM) communicates with the vehicle through the high speed CAN C bus. The ITBM monitors the Brake Pedal Status, Vehicle Speed and ESP status via CAN message. It also outputs the Trailer Status, Gain Setting, and Trailer Brake Output Power to the vehicle. The ITBM connects to the electric trailer brakes through the 7-Way connector and controls the brake force through a Pulse Width Modulating (PWM) duty cycle.
Note. If there is no trailer connected there will be NO Pulse Width Modulating (PWM) signal.
The PWM is proportional to the rate of deceleration measured by the accelerometer inside the ITBM. The ITBM controls the PWM output to the trailer brakes in four ways. The first occurs while the brake pedal becomes active and vehicle speed is greater than 0 km/h (0 mph). The second is the manual lever on the ITBM that can be controlled by the driver. If both the manual lever and the brake pedal are active simultaneously, the greater of the two, in terms of PWM output, will prevail. The third is after the vehicle has stopped moving, after approximately three seconds of the brake pedal applied the trailer brakes will be applied too. This is to minimize hitch to trailer noise and vehicle roll back when taking off from a stop and on an incline. The fourth is that it will become active during an ESP trailer sway event.
ELECTRONIC TRAILER BRAKE MANUAL LEVER FAILSAFE CIRCUIT-PERFORMANCE OR INCORRECT OPERATION
For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .
The Integrated Trailer Brake Module (ITBM) communicates with the vehicle through the high speed CAN C bus. The ITBM monitors the Brake Pedal Status, Vehicle Speed and ESP status via CAN message. It also outputs the Trailer Status, Gain Setting, and Trailer Brake Output Power to the vehicle. The ITBM connects to the electric trailer brakes through the 7-Way connector and controls the brake force through a Pulse Width Modulating (PWM) duty cycle.
Note. If there is no trailer connected there will be NO Pulse Width Modulating (PWM) signal.
The PWM is proportional to the rate of deceleration measured by the accelerometer inside the ITBM. The ITBM controls the PWM output to the trailer brakes in four ways. The first occurs while the brake pedal becomes active and vehicle speed is greater than 0 km/h (0 mph). The second is the manual lever on the ITBM that can be controlled by the driver. If both the manual lever and the brake pedal are active simultaneously, the greater of the two, in terms of PWM output, will prevail. The third is after the vehicle has stopped moving, after approximately three seconds of the brake pedal applied the trailer brakes will be applied too. This is to minimize hitch to trailer noise and vehicle roll back when taking off from a stop and on an incline. The fourth is that it will become active during an ESP trailer sway event.