ELECTRICAL SYSTEM CONTINUED
These sensors continuously inform the ECM of the position of a particular lever or pedal that is controlled by the
operator. The operator selects the position and the sensor indicates the position to the ECM. Each position sensor
sends a pulse width modulated signal (PWM) to the ECM. A PWM signal is a square wave signal that is
approximately between 0 VDC to 5 VDC.
Position Sensor (Brake Pedal)
This sensor continuously informs the ECM of the position of the brake pedal and is located on the linkage of the
brake pedal. The ECM uses the duty cycle of the signal in order to determine the rate of modulation for the brakes.
The duty cycle increases as the pedal is pressed. When the brake pedal is fully pressed, an additional brake
function is activated. The service brake switch on the brake pedal closes and the secondary brake solenoid is
energized. This relieves hydraulic pressure to the brakes, which will cause the brakes to engage.
Figure 14. Position Sensor for the Brake Pedal.