F 350 4WD Super Duty V10-6.8L VIN Y (2006)
F4
Test G: The Trailer Brakes Are Always Engaged
PINPOINT TEST G: THE TRAILER BRAKES ARE ALWAYS ENGAGED
Normal Operation
The braking energy that is provided to the trailer is varied with a pulse width modulated (PWM) signal that switches between 0 volt and battery
voltage, according to the TBC gain setting, the higher the duty cycle the more braking power available. With the vehicle stationary and with the
manual slider switch fully to the left with a gain of 10, there should be greater than 10 - 12 volts supplied to trailer tow C4099-3 circuit 43 (DB).
Possible Causes
^
Fuse(s)
^
Circuit open
^
Circuit shorted
^
Corrosion
^
Pushed-out pins
^
Trailer circuitry
^
TBC module
G1-G2
